JUVENILE PRIMARY FIBROMYALGIA SYNDROME

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1 138 JUVENILE PRIMARY FIBROMYALGIA SYNDROME A Clinical Study of Thirty-Three Patients and Matched Normal Controls MUHAMMAD B. YUNUS and ALFONSE T. MAS1 Primary fibromyalgia syndrome (PFS) is a common and characteristic rheumatologic condition manifested by diffuse musculoskeletal aches, pains, and stiffness frequently modulated by various factors, e.g., weather, physical activity, sleep quality, and anxiety/ stress, and accompanied by discrete tender points at typical soft tissue sites. Although well-recognized in adults, this entity has not been reported separately in juveniles. This study documents PFS in 33 juveniles who presented at age 17 or younger and compares their findings with those in age- and sex-matched normal control subjects. As in adult PFS patients, associated non-musculoskeletal symptoms were common, including fatigue, poor sleep, anxietyhtress, headaches, and paresthesias. Physical examination revealed multiple tender points at characteristic soft tissue sites and no objective evidence of arthritis. Routine laboratory test results were normal or negative. Juvenile PFS is often misdiagnosed. Recognition of this common rheumatologic condition in juveniles is important in order to avoid unwarranted investigations and improper management. Fibromyalgia syndrome, a form of nonarticular - From the Department of Medicine, Division of Rheumatology, University of Illinois College of Medicine at Peoria, Peoria, Illinois. Supported in part by National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases grant AM Muhammad B. Yunus, MD: Assistant Professor of Medicine; Alfonse T. Masi, MD, DrPH: Professor and Head, Department of Medicine. Address reprint requests to Muhammad B. Yunus, MD, Department of Medicine, University of Illinois College of Medicine at Peoria, P.O. Box 1649, Peoria, IL Submitted for publication April 27, 1984; accepted in revised form September 24, rheumatism manifested by diffuse musculoskeletal aching and tender points at multiple characteristic sites, is now established as a recognizable clinical entity in adults (1-4). We prefer the term primary fibromyalgia syndrome (PFS) rather than fibrositis to underscore the absence of an underlying condition (e.g., rheumatoid arthritis, osteoarthritis, trauma, or hypothyroidism) which may also be associated with similar clinical features. This term also indicates lack of inflammation on muscle biopsy (5,6), as well as presence of non-musculoskeletal features (3,7). Although PFS is now well described in adults, this syndrome is not generally recognized among juveniles and has not been separately described in this age group. This report presents detailed results of a clinical study of PFS in 33 juveniles and matched normal controls. PATIENTS AND METHODS Thirty-one patients were white and 2 were black, and all but 2 were females. They had an age range of 9-17 years at presentation (mean 14.7; median 15). The age of the normal controls ranged from 9-19 years (mean 14.5; median 15). Onset age of PFS ranged from 5-17 years (mean 12.3; median 13.5). The presentation and onset ages of patients by subgroups are shown in Table 1. The most frequent age group for both presentation and onset was years. All but 1 patient had onset before age 16, and 29 (88%) of the 33 patients presented between ages 13 and 17. The presentation and onset ages of the 2 male patients were 15 and 14, and 14 and 10, respectively. The mean (% 1 SD) height of patients was 157? 11.2 cm and of controls 154.7? 9.8 cm, with no significant difference. The mean weight of patients was 45.7 * 12.1 kg and of controls 39.6 % 7.0 kg (P < 0.06). The mean observed subjectlstandard height and weight ratios, according to age Arthritis and Rheumatism, Vol. 28, No. 2 (February 1985)

2 ~~~~~~ JUVENILE PFS 139 Table 1. Distribution of presentation and onset ages in 33 juvenile primary fibromyalgia syndrome patients Age group (vears) Presentation Onset Total (0%) 4 (12%) 3 (9%) 5 (15%) 1(3%) 4 (12%) 16 (49%) 19 (58%) 13 (39%) I(3%) 33 (100%) 33 (1009%) (S), were also calculated for patients and controls, with no significant difference. All 33 patients were age 17 or younger at presentation, and were seen consecutively by us in ambulatory rheumatology consultation. Older patients with juvenileonset symptoms were not included. The age limit of 17 at presentation was chosen instead of the suggested pediatric age limit of 20 (9), or onset before age 16 as is the case for juvenile rheumatoid arthritis (lo), because many pediatric services include patients until age 17 (which is also the maximum legal age for juveniles). The juvenile presentation age is more reliable than onset age for consistency among centers and for correct diagnosis of juvenile primary fibromyalgia, since time of symptom onset of this condition may not be accurately recalled later in adult years and other conditions at onset, e.g., viral arthralgia or arthritis, cannot be ruled out by recall of symptoms alone. Data were collected longitudinally by one of us (MBY) according to a standardized protocol which included a physician-administered questionnaire and a physical examination form, as in our previous PFS study (3). All patients had as entry criteria musculoskeletal aching or stiffness for at least 3 months that involved 3 or more areas, as well as at least 4 well-defined tender points (3). None had an underlying condition, including obvious trauma or hypermobility syndrome, to explain their symptoms and signs. None had evidence of synovitis, muscle weakness, or neurologic abnormality. All the usual laboratory test results were normal or negative, including complete blood count, Westergren erythrocyte sedimentation rate, muscle enzymes, serum electrolytes, serum calcium, urinalysis, rheumatoid factor by latex fixation, and roentgenograms of prominently involved sites. Two female patients had positive antinuclear antibody tests in low titers (both 1 :80, speckled pattern) without an underlying cause, including drug or connective tissue disorder, on followup at 15 and 18 months. Test results for serum C3 and C4 and antibodies to native DNA, Sm, and RNP were normal or negative. No patient had clinical hypothyroidism, and thyroid function tests performed on 12 patients had normal results. Entry criteria did not include strict counting of a required number of minor associated criteria (e.g., fatigue, poor sleep, anxiety) as previously suggested (3). However, clinical diagnosis quite likely involved some consideration of these suggested minor criteria. Normal controls were chosen from among the friends of patients and were matched for sex, race, and age (k2 years). Six normal controls had musculosketal pain in 1 or more areas for which they did not seek physician consultation. Tender points were defined as areas of exaggerated tenderness elicited on moderately firm fingertip palpation of specific anatomic sites (3); comparatively less pressure was applied than in adults. Only a response of severe (compared with mild or moderate) pain, physical withdrawal of the local part, characteristic body recoil ( jump sign ), or facial expression of pain qualified as a tender point (3). Differences between patients and controls and between patient subgroups in proportionate frequencies of dichotomous (yesho) variables were evaluated using the chisquare test with Yates correction, as appropriate, or Fisher s exact test. Continuous variables were analyzed by Student s t-test or were dichotomized at critical levels and subjected to chi-square or Fisher s exact test. as mentioned above (1 I). RESULTS Frequency of symptoms (Table 2). Diffuse musculoskeletal aching was present in 32 patients (97%); 1 patient consistently complained of stiffness only. Stiffness was present in 79% and subjective soft tissue swelling in 61% of the patients. Non-musculoskeletal symptoms were common, including general fatigue throughout the day in 91%. Although 67% reported not sleeping well, all patients woke up tired in the morning, implicating nonrestorative sleep. Chronic headaches, not due to sinusitis and often related to tension, were reported in 54%, numbness in 36%, and irritable bowel symptoms (altered bowel habits associated with abdominal pain or discomfort) in 27%. Anxiety and depression were self-assessed either by patients and controls or occasionally by their accompanying parent(s); responses were elicited to the questions do Table 2. Percent frequency of symptom manifestations in 33 juvenile primary fibrornyalgia syndrome (PFS) patients and 33 matched normal controls Symptom Juvenile Normal manifestations PFS patients controls Musculoskeletal Generalized aches and pains Stiffness Subjective soft tissue swelling Non-musculoskeletal Waking up tired General fatigue Anxiety Poor sleept Depression Chronic headaches Numbness Irritable bowel symptoms * Differences were significant at P < or lower, except for anxiety and irritable bowel symptoms, which were significant at P < t Indicates negative response to the question do you deep well?

3 140 YUNUS AND MAS1 Table 3. Frequency (%) of sites of aches, pains, or stiffness in 33 juvenile primary fibromyalgia syndrome patients* Site % Site % - - Knees 67 Trapezius (upper border) 24 Ankles 42 PIP joints (hands) 24 Elbows 39 Upper lateral thigh 24 Lower back 33 MCP joints 18 U ppedmid-back 30 Fingers 18 Wrists 27 Thighs (diffuse) 15 Cervical spine 27 Feet 12 * PIP = proximal interphalangeal; MCP = metacarpophalangeal you regard yourself an anxious or worrying type of person? and do you usually feel depressed or low in spirit? respectively. All symptoms were significantly more frequent among patients than controls. Sites, duration, and diurnal variation of symptoms. Common sites of aches, pains, or stiffness are shown in Table 3. Aches and pains were symmetric (bilateral in more than 80% of affected sites) in 79% of patients. Total sites of aches and pains among the patients ranged from 4 to 34 (mean 13; median 12), compared with 0 to 5 in the normal controls. Subjective swelling, when reported (61%), involved 1 to 11 sites (mean 8.1 ; median 9), commonly in or around knees (45% of patients), followed by metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of hands and fingers (18% each), wrists and ankles (15% each). Numbness, when present (36%), was described in 1 to 12 sites (mean 8; median 71, commonly in fingers (52%), hands (24%), and legs (18%). Duration of aches, pains, or stiffness in patients ranged from 3 to 122 months (mean 30; median 12). Only 1 control subject had aches and pains in 3 or more sites for 3 or more months (but had only 4 tender points). Four controls had pain in 2 anatomic sites each, and another in I site. Each PIP or MCPjoint area (if specified by the patient), a finger, hand or foot, 1 arm, leg or thigh, cervical spine, upper or mid-back, and lower back were counted as a single site. Aches and pains were present mostly in the morning in 45%, morning as well as afternoon or evening in 35%, no particular time in 13%, and mostly in the afternoon or evening in 7% of patients. Stiffness was present mostly in the morning in 75%, lasting 10 minutes to all day (mean 107 minutes; median 60), mostly in the morning and afternoon or evening in 12.5%, and at no particular time in 12.5%. Modulating factors. Factors reported to modulate aches, pains, or stiffness are shown in Table 4. Common aggravating factors were cold andlor humid weather, physical overactivity or inactivity, anxiety/ stress, and poor sleep. Commonly, a hot shower or bath, stretching exercises, warm weather, moderate activity, and massage helped alleviate musculoskeletal aching or stiffness. Physical examination. The patients mean pulse rate of 76/minute and systolic blood pressure (BP) of 111 were not significantly different from those of the matched controls (75 and 104, respectively). However, the mean diastolic BP of 75 among the patients was significantly greater than that of 65 among the controls (P < 0.01), with no correlation between weight and BP in either group. No patient had definite synovitis, including objective joint swelling. However, 1 of the 20 patients complaining of soft tissue swelling also demonstrated mild to moderate diffuse soft tissue swelling of fingers on examination; results of a bone scan in this patient were normal. The most significant finding among the patients was the presence of multiple tender points (range 5-31; mean 13; median 12). Although 36% of the normal controls had 1 or more tender points, none had more than 4 (range 0 to 4, mean 0.8) (P < 0.001). Common sites of tender points are shown in Figure 1. The PIP and MCP joints of the hands were tender in 3 and in 2 patients, respectively. The normal controls had tender points, with significantly less frequency than patients, in the following sites: lateral part of elbows (27%), sternomastoid muscles (18%), medial part of elbows (12%), suboccipital areas (6%), posterior iliac crest (medial aspect), costochondral junctions, and thoracic spine/paraspine (each 3%). In view of the median presentation age of 15, the 20 patients who presented at age 15 or younger were compared with the 13 patients who presented at ages 16 and 17. No significant difference was found between these 2 groups in any variables except height and weight (P < 0.05). Table 4. Frequency (%) of factors reported to modulate aches, pains, or stiffness in 33 juvenile primary fibromyalgia syndrome patients Aggravating factors YO Relieving factors 70 Cold/humid weather 88 Hot showedbath 85 Physical overactivity 88 Stretching exercises 58 Physical inactivity 64 Warm weather 58 Anxiet yistress 45 Moderate activity 55 Poor sleep* 39 Massage 55 Air conditioningt 18 General rest 27 * Poor sleep defined as not sleeping well. t Spontaneous response; not included in protocol questionnaire.

4 JUVENILE PFS % Figure 1. Frequency distribution of common tender points in 33 juvenile primary fibromyalgia syndrome patients; % = percent of positive patients. Preceding diagnoses and unwarranted investigations. More than half the patients (55%) did not have a definite diagnosis on referral. Referral diagnoses included juvenile rheumatoid arthritis in 8 patients, arthritis in 4, and collagen disease in 1. Only 1 patient had a diagnosis of fibromyalgia ( fibrositis ). Nearly half the patients had 1 or more unwarranted investigation(s), including arthrograms in 4, bone scans in 4, brain scans in 4, myelogram in 1, and spinal tap in 1. Electroencephalograms (EEGs) were performed on 3 patients because of headaches, numbness, or subjective weakness. One patient was treated with oral corticosteroids because of a presumed diagnosis of collagen disease. Degree of disability, symptom status on followup, and school absenteeism. Information on these features was available in 20 juveniles. At presentation, patients were asked to self-assess their degrees of disability as none, mild, moderate, or severe, considering how much their musculoskeletal symptoms interfered with their normal life activities. All patients reported some disability, graded as mild in 4 (20%), moderate in 12 (60%), and severe in 4 (20%). At presentation, symptoms were graded as mild in 5%, moderate in 45%, and severe in 50%. At followup, after a mean period of 18.8 months (range 4-52; median 14), symptoms had generally improved and were absent in S%, mild in 55%, moderate in 40%, and severe in none (P < 0.OOl). Juveniles who slept well at the time of referral did better at followup than those who did not (P < 0.05). The mean number of days lost from school because of musculoskeletal pain prior to referral was 5.8 t 8.3, 9.4 * 9.9, and 13 t 17.7, in 3, 6, and 12 months, respectively. FolIowup disability was not assessed. DISCUSSION This study, based on 33 juvenile patients and 33 matched normal controls, shows that PFS in juveniles, like that in adults (1-3,7), is a characteristic nonarticular rheumatic syndrome. Both juveniles and adults manifest diffuse musculoskeletal aching and/or stiffness with characteristic modulating factors. Manifestations of a systemic disease, e.g., weight loss, fever, skin rash, and poor appetite, are absent. Physical examination shows no evidence of synovitis, muscle weakness, or neurologic abnormality, but multiple soft tissue tender points are evident at characteristic sites, as was earlier reported in adult PFS patients (3). Symptoms and tender point sites are consistent and reproducible at followup. Routine laboratory test results are normal. Adult PFS and juvenile PFS are similar conditions, although several differences were noted among the present series of 33 juvenile patients when compared with the 39 adults (age 18 and older) in our previous series (3). Among the juveniles, certain features were more common, i.e., subjective swelling (61% versus 23%; P < 0.005), ankle pain (42% versus 15%; P < 0.05), and aggravation of pain by overactivity (88% versus 59%; P < 0.05), whereas others were less frequent, i.e., low back pain (33% versus 69%; P < 0.005), hand pain (33% versus 69%; P < 0.005), symptom aggravation by anxiety (45% versus 74%; P < 0.05), symptom relief by moderate activity (55% versus 85%; P < 0.05), as well as warmidry weather (58% versus 85%; P < 0.05), and tender point at lumbar spine/paraspine area (33% versus 62%; P < 0.05). The different frequency of tender points at the suboccipital region is explained by a different (and more sensitive) technique of palpation in our present series (palpation of rectus capitis posterior insertion,

5 142 YUNUS AND MAS1 rather than below the superior nuchal line). Overall, these relatively few differences between juveniles and adults should be accepted with certain reservations. Subjective perception of symptoms and their reporting may be different and less consistent among the younger juveniles compared with the adults. PFS, either in adults or juveniles, may be questioned as an entity because no definite physical or laboratory findings are present, or it may be regarded as merely an expression of anxiety or depression. Our psychological studies among adults have shown that only one-third of patients are disturbed psychologically according to the Minnesota Multiphasic Personality Inventory, with high scores on the Depression scale (12,13). Thus, not all PFS patients are unduly anxious or depressed. Psychological studies are not available on juvenile PFS at this time, but our general observations suggest that psychological factors in juveniles are probably similar to adults. The American Psychiatric Association (APA) guidelines for diagnosis of psychogenic pain include absence of adequate physical findings or pathophysiologic mechanisms for pain (14). In PFS, the tender points on physical examination are usually at specific sites, are consistent, and are reproducible. As in tension headaches, muscle spasm, observed in many patients, probably forms a pathophysiologic basis of PFS. Tension headaches, present in half of our juvenile patients, have specifically been excluded from the APA category of psychogenic pain (14). Anxiety and stress are important contributory factors for such well-accepted entities as irritable bowel syndrome (IBS) and tension headaches, both of which lack definite physical and laboratory findings and are associated with PFS (3). Conceptually, IBS, PFS, and tension headache syndrome are similar conditions with muscle spasm as a probable pathophysiologic mechanism common to all (15). PFS and IBS have many common and overlapping features (15-17). IBS occurs both in adults and juveniles (17,18). It appears that multiple factors, e.g., constitutional factors, poor sleep, anxietylstress, subclinical trauma, and poor posture are contributory in PFS. Objective sleep EEG studies have shown disturbed non-rapid eye movement sleep among adult PFS patients (19). Previous description and prevalence of juvenile PFS. Bates and Grunwaldt described 62 children aged 3-18 years with trigger areas among 85 juveniles with myofascial pain caused by a variety of underlying illnesses and injuries (20). These juveniles with nonspecific and heterogeneous myofascial pain are differ- ent from our PFS patients, since pain and tender points in these patients were secondary to other conditions, e.g., obvious trauma and infection (20). Prevalence of juvenile PFS cannot be accurately estimated at this time, but it appears to be common. Over a period of 18 months, from January 1981 to July 1982, we saw 19 new juvenile rheumatoid arthritis (JRA) patients, age 17 years or younger at presentation. We saw 15 new juvenile PFS patients who presented at age 17 years or younger during the same period. However, if adult PFS patients with symptom onset under age 16 are accepted as having juvenile PFS (as is the case in JRA), then the number of juvenile PFS was 24, compared with 22 JRA patients with onset age under 16 years. Clinical features of juvenile PFS. Several features merit discussion. Subjective swelling of soft tissues may be present in both articular and periarticular locations, leading to a misdiagnosis of arthritis, as was the case in 8 patients. Except in 1 patient, the soft tissue swelling was not objectively seen. However, it is possible that the degree of such swelling is not severe enough to be detected by physical examination. This symptom was not related statistically to anxiety or numbness, but to increased number of pain sites (P < 0.05). It was also significantly more common among juveniles who were physically more active (P < 0.05). Although a history of definite or obvious trauma was uniformly negative, subclinical trauma or overuse may thus play a role. Numbness is another feature which did not correlate with anxiety. It may be attributed to altered sensory perception by PFS patients, possibly associated with localized muscle spasm. Neurologic symptoms, including numbness, headaches, and subjective fatigue, are important features of PFS. These symptoms may contribute to unwarranted investigations, e.g., electroencephalograms, brain scans, and myelograms, if the syndrome is unrecognized. Anxiety and depression were assessed by the patients and occasionally by their parents, as explained earlier. These, as well as other, symptoms which require subjective assessment (e.g., modulating factors of aches and pains) are likely to be less reliable and consistent in juveniles than adults, particularly among the younger children. Further, patients or their parents may report anxiety or stress as rationalization of patients symptoms. Psychological studies using appropriate tools for children may provide a better evaluation of anxiety, stress, and depression in juvenile PFS.

6 JUVENILE PFS 143 Poor sleep is an important symptom and is likely to contribute to overall aching (19). Although 67% reported that they do not sleep well, all patients reported fatigue on awakening, implicating nonrestorative sleep (19,21). Morning fatigue may be a more sensitive indicator of nonrestorative sleep than a general statement of not sleeping well. General fatigue during the day is also present in nearly all of the juvenile patients (91%), as in the adults (3). Our previously demonstrated association of irritable bowel syndrome with PFS was also found in another study (4), and in this juvenile series. Anxiety/ stress is likely to be a common associated factor in both PFS and IBS. Symptoms were significantly more common among the patients than the normal controls. This is in part due to physician selection of PFS symptoms. However, all PFS symptoms, e.g., minor criteria (3,7), were not methodically sought by a physician as entry criteria, although use of clinical judgement in diagnosis is likely to have included some of these symptoms. Although diffuse soft tissue tenderness may be present in some patients (1,22), localized tenderness at characteristic sites is more usual on physical examination (Figure 1). Distant radiation of pain from site of palpation is rare (22), and thus the term trigger point (23) is inappropriate in general, as opposed to the preferred term tender point. One of our patients presented with pain and tenderness in the temporomandibular joints (TMJ). Fifteen percent had TMJ tenderness in this study. Such tenderness cannot be differentiated from that in TMJ syndrome. However, it is of interest that the most common cause of TMJ syndrome is functional (24). Some PFS patients do have features of this syndrome. Differential diagnosis. Differentiation of other conditions mimicking juvenile PFS has been fully reviewed elsewhere (25). Juvenile rheumatoid arthritis can be distinguished by objective arthritis and other features (26). Similarly, traumatic arthritis, bursitis, tendinitis, and muscle sprain are differentiated from PFS by history as well as the localized nature of these conditions (in contrast to generalized manifestations in PFS) (2$,27). Systemic lupus erythematosus is characterized by its clinical and immunologic features (28). Psychogenic pain is a different entity with bizarre, highly emotional, and highly inconsistent symptoms; patients are tender everywhere, even when touched gently (3). Growing pains with musculoskeletal aching in the absence of an abnormal laboratory test result (29,30) might have been confused with juvenile PFS in the past, although tender points were not described in the former. If this term is to be used at all, only patients with nocturnal limb pain (29-3 1) should be included in this category. Nocturnal pain did not occur predominantly in any of our 33 patients. Some patients with hypermobility of joints have rheumatic symptoms, including myalgia and arthralgia. A diagnosis of hypermobility can be made by the suggested criteria of Beighton and Horan (32). However, patients with hypermobility were excluded from this study. Children with school phobia may have headaches, abdominal pain, and, less commonly, vague body pain, but such symptoms usually occur before school time (33). Suggested criteria for diagnosis of juvenile PFS. All 33 juveniles in this series and none of the matched normal controls satisfied our previously suggested criteria for PFS (3,7,27). These criteria include generalized musculoskeletal aching at 3 or more sites for 3 or more months in the absence of an underlying condition, e.g., arthritis and obvious trauma. Results of the usual laboratory tests are normal. In addition, 5 or more typical tender points plus 3 of the following 10 features (minor criteria) should be present: 1) chronic anxiety or tension; 2) fatigue; 3) poor sleep; 4) chronic headaches; 5) irritable bowel syndrome; 6) subjective soft tissue swelling; 7) numbness; 8) pain modulation by physical activities; 9) pain modulation by weather factors; and 10) pain modulation by anxietylstress. Four tender points will also satisfy the criteria, provided a patient has 5 of the above 10 features. In this study ofjuveniles, 1 normal control, who had aches and pains at 5 anatomic sites for 4 months, had only 4 tender points and 2 minor criteria, and thus did not satisfy the above criteria. Of the 10 suggested minor criteria, juveniles were significantly different in only 3 (increased frequency of pain aggravation by overactivity and equally decreased frequency of pain relief by moderate activity in juveniles cancelled each other). Frequency distribution of these 3 criteria balanced each other, subjective swelling being more common in juveniles, whereas pain modulation by anxiety and weather is more common in adults. Independently-derived criteria for juvenile PFS, including other control conditions with musculoskeletal aching, e.g., JRA and hypermobility syndrome, will be needed for a future study. Whether the onset age, or age at presentation, under 17 or 18 years should be accepted as criteria for diagnosis of juvenile PFS is open to discussion. In this study, no significant difference was found between

7 144 YUNUS AND MAS1 children who presented at age 15 and younger versus those who presented at age 16 and 17. Incidentally, only 1 patient had onset age over age 15 in this study. As explained in Patients and Methods, it may be preferable to classify juvenile patients according to presentation rather than onset age. Symptoms at followup. Symptoms at followup generally improved among our patients. Optimal management, including a firm diagnosis, reassurance regarding benign nature (compared with juvenile rheumatoid arthritis), management of stress factors if present, moderation of physical activity, physical therapy (heat, stretching exercises), simple, non-addictive analgesics, and a nonsteroidal antiinflammatory agent also contributed to less severe symptoms at followup. Any implication that the pain is all psychological should be avoided. Management of juvenile PFS is similar to that of adults (3,7,34), but psychoactive drugs should rarely be used in children. Long-term prognosis of juvenile PFS remains unknown, and needs to be determined in a longitudinal study. From our experience of adult PFS patients with juvenile onset, it appears that symptoms of juvenile PFS may go away in some patients, only to return later in adult life. In conclusion, juvenile PFS is a common and recognizable condition which should be diagnosed by its own characteristic features and not merely by exclusion of other conditions. Diagnosis of juvenile PFS is important to avoid unwarranted investigations and improper management. ACKNOWLEDGMENT We greatly appreciate the technical assistance of Barbara Lundeen in this study. REFERENCES Tout EF: Fibrositis. J Am Geriatr SOC , 1968 Smythe HA: Non-articular rheumatism and psychogenic musculoskeletal syndromes, Arthritis and Allied Conditions. Ninth edition. Edited by DJ McCarty. Philadelphia, Lea & Febiger, 1979, pp Yunus M, Masi AT, Calabro JJ, Miller KA, Feigenbaum SL: Primary fibromyalgia (fibrositis): clinical study of 50 patients with matched normal controls. Semin Arthritis Rheum 11; , 1981 Campbell SM, Clark S, Tindall EA, Forehand ME, Bennett RM: Clinical characteristics of fibrositis. I. A blinded, controlled study of symptoms and tender points. Arthritis Rheum , Yunus MB, Kalyanraman UP, Kalyanraman K, Masi AT, Berg BC: Microscopic and radioactive bone scan studies in primary fibromyalgia (abstract). Arthritis Rheum (suppl) 25:S146, Kalyanraman UP, Kalyanraman K, Yunus MB, Masi AT: Muscle pathology in primary fibromyalgia syndrome (PFS): a light microscopic, histochemical and ultrastructural study. J Rheumatol 11: , Masi AT, Yunus MB: Primary fibromyalgia syndrome: a commonly unrecognized rheumatologic disorder. Continuing Ed Fam Phys 17:19-32, Tanner JM: Physical growth and development, Textbook of Pediatrics. Edited by JO Forfar, GC Arneil. London, Churchill Livingstone, Council on Child Health, American Academy of Pediatrics: Age limits of pediatrics. Pediatrics 49:463, JRA Criteria Subcommittee of the Diagnostic and Therapeutic Criteria Committee of the American Rheumatism Association: Current proposed revisions of the JRA criteria. Arthritis Rheum (suppl) 20: , Nie NH, Hull CH, Jenkins JG, Steinbrenner K, Bent DH: Statistical Package for the Social Sciences (SPSS). New York, McGraw-Hill, Ahles TA, Yunus MB, Riley SD, Bradley JM, Masi AT: Psychological studies in primary fibromyalgia syndrome (abstract). Clin Res 31:801A, Ahles TA, Yunus MB, Riley SD, Bradley JM, Masi AT: Psychological factors associated with primary fibromyalgia syndrome. Arthritis Rheum 27: , Diagnostic and Statistical Manual of Mental Disorders (DSM 111). American Psychiatric Association, 1980, pp Yunus MB: Primary fibromyalgia syndrome: current concepts. Compr Ther 10:21-28, Yunus MB: Fibromyalgia syndrome: a need for uniform classification (editorial). J Rheumatol 10: , Kirsner JB: The irritable bowel syndrome. Arch Intern Med 141: , Barber0 GJ, McKay RJ: Irritable bowel syndrome, Nelson s Textbook of Pediatrics. Edited by RE Behrman, VC Vaughn 111. Philadelphia, WB Saunders, 1983, pp Moldofsky H, Scarisbrick P, England RE, Smythe H: Musculoskeletal symptoms and non-rem sleep disturbance in patients with fibrositis syndrome and healthy subjects. Psychosom Med 37: , Bates T, Grunwaldt E: Myofascial pain in childhood. J Pediatr 53: , Moldofsky H, Lue FA: The relationship of alpha and delta EEG frequencies to pain and mood in fibrositis patients with chtorpromazine and L-tryptophan. Electroencephalogr Clin Neurophysiol 50:71-80, I Yunus MB, Masi AT: A detailed and controlled clinical study of primary fibromyalgia syndrome. In preparation 23. Kraus H: Trigger points. NY State J Med 73: , 1973

8 JUVENILE PFS , Sheon RP, Moskowitz RW, Goldbert VM: Soft Tissue the first two decades of life. Am J Med , 1977 Rheumatic Pain. Philadelphia, Lea & Febiger, 1982, pp 29. Ansell BM: Rheumatic Disorders in Childhood. Lon don, Butterworths, 1980, pp 2-3 Yunus MB: Aches and pain: is it juvenile fibromyalgia 30. gster J, Nielsen A: Growing pains: a clinical investigasyndrome? Diagnosis 6:93-102, 1984 tion of a school population. Acta Paediatr Scand 61 :329- Calabro JJ, Holgerson WB, Sonpal GM, Khoury MI: 334, 1972 Juvenile rheumatoid arthritis: a general review and 31. Calabro JJ, Wachtel AE, Holgerson WB, Repice MM: report of 100 patients observed for 15 years. Semin Growing pains. Postgrad Med 59:66-72, 1976 Arthritis Rheum 5: , Beighton P, Horan S: Orthopedic aspects of the Ehlers- Yunus MB: Primary fibromyalgia syndrome: diagnosis Danlos syndrome. J Bone Joint Surg 51B: , 1969 and differential diagnosis. IM-Int Med Specialist Gelbert E: Psychosocial Aspects of Pediatric Care. New 74, 1983 York, Grune & Stratton, 1978, pp Fish AJ, Blau EB, Westberg NG, Burke BA, Vernier 34. Yunus MB, Masi AT, Calabro JJ, Shah IK: Primary RL, Michael AF: Systemic lupus erythematosus within fibromyalgia. Am Fam Physician 25: , 1982 Erratum There was an error in Table 2 of an article which appeared in the October 1984 issue of Arthrrtrs and Rheumatism (Ahles TA, Yunus MB, Riley SD, Bradley JM, Masi AT: Psychological Factors Associated with Primary Fibromyalgia Syndrome. Arthritis Rheum 27:llOl-1106, 1984). The first two values in the table column marked RA were listed as 44.8 and These values should have been 46.6 and 46.6.