MERCY RETREAT Dermatology

Transcription

1 MERCY RETREAT 2016 Dermatology

2 INFECTIONS IN DERMATOLOGY Why we do talk about infections today? These are some of the most commonly seen dermatologic diseases that present to primary care physician office However, we had only minimal exposure of what to look for in medical school Important to have a good mental model of what to look for when evaluate these patients At the end of the day, dermatology is a field of pattern recognition. We group skin rashes into different morphologies to help us figure out exactly what disease we are looking at. There are many common confusions around diagnosing and managing these infections We will talk about common pitfalls in diagnosis and treatment

3 MYSTERY CASE

4 TINEA

5 DERMATOPHYTES BACKGROUND Group of closely related organisms capable of infecting keratinized skin and its appendages Acquired by contact with infected person, animal or infected soil Recurrent course Most common types Tinea corporis Tinea cruris Tinea pedis/manuum Onychomycosis (nail fungus) / tinea unguium Tinea capitis Tinea barbae/faciei

6 DERMATOPHYTES PREDISPOSING FACTORS Heat Humidity Perspiration Maceration Irritation Occlusion (clothing, shoes)

7 DERMATOPHYTES TINEA PEDIS Tinea pedis ( athlete s foot ) is the most common fungal infection seen in developed countries Most commonly caused by the fungus Trichophyton rubrum Fungus thrives in warm, moist environment (e.g., shoes) Public showers, gyms are common sources of infection Good foot hygiene may reduce recurrences There are three clinical patterns of infection: interdigital, moccasin, and vesiculobullous type

8 TINEA PEDIS EXAMPLES Moccasin Interdigital Vesicular

9 TINEA PEDIS MOCCASIN TYPE (WITH MANUUM) Moccasin type may present as one hand, two feet syndrome. Affected hand shows unilateral fine scaling in the creases. If you see a hand like this, look at the feet as well.

10 TINEA CORPORIS BACKGROUND Tinea corporis, ringworm, refers to dermatophytosis of the skin, usually affecting the trunk and limbs Often itchy The margin of the lesion is the most active; central area tends to heal Scrapings should be taken from the red scaly margin for KOH exam A variant of this is tinea cruris or jock itch, which has a similar presentation but appears in the groin Check the bottom of the feet for tinea pedis Morphology in this case is erythematous, scaly, annular plaque/patch with advancing borders

11 TINEA CORPORIS EXAMPLES

12 TINEA CORPORIS - EXAMPLES

13 TINEA CRURIS - BACKGROUND Dermatophyte infection of the groin is called tinea cruris (aka jock itch ) May lack scale because of scrotal occlusion Look at the soles for tinea pedis

14 TINEA UNGUIUM - BACKGROUND Onychomycosis is a chronic fungal infection of the nailbed Usually starts with tinea pedis Responds very poorly to topical antifungals

15 TINEA UNGUIUM EXAMPLES

16 TINEA CAPITIS BACKGROUND

17 DERMATOPHYTE WORK UP KOH Prep One should always confirm the diagnosis of tinea with KOH prep first before giving antifungal Too often does practitioner skip this very important step and just try to treat without finding the fungal element This is especially important when you re planning on giving oral antifungal

18 DERMATOPHYTE WORK UP Parallel walls throughout the entire length Septated and branching hyphae

19 DERMATOPHYTE KOH PREP

20 DERMATOPHYTE TREATMENT Topical Antifungal Clotrimazole, econazole, miconazole, ketoconazole Works okay for tinea pedis in otherwise healthy adults Dermatophytes can invade down to Adamson s fringe so topicals don t work well in hair-bearing areas because topical cannot penetrate that deep Oral Medication Griseofulvin tinea capitis, corporis, cruria, pedis Terbinafine tinea pedis, unguium Fluconazole tinea unguium Adamson's Fringe

21 DERMATOPHYTE ORAL ANTIFUNGAL Check CBC and LFTs Remember that young children can have elevated alkaline phosphatase, which can be normal Should not drink alcohol when taking oral antifungal Griseofulvin Tinea capitis, tinea corporis, tinea cruris, tinea manuum / pedis Terbinafine Tinea unguium / onychomycosis, tinea pedis

22 MYSTERY CASE TINEA INCOGNITO

23 MORE TINEA EXAMPLES Tinea manuum Tinea corporis

24 TINEA - SUMMARY Look for erythematous, scaly, annular patch with scale most notably on the advancing edge Do not forget that diagnosis is best made with KOH prep Unless you re treating groin area or just trying to maintain an area rather than cure an area (e.g., 80 yo patients with tinea pedis), use oral antifungal over topical antifungal Also, please dose appropriately. Common failure of treatment is actually underdosing the medication, especially in pediatric patient populations

25 MYSTERY CASE

26 SCABIES

27 SCABIES BACKGROUND Also known as the seven-year itch Contagious infestation by the mite Sarcoptes scabiei Must check areas: Hands (wrists and in between fingers) Genitalia (especially penis) Commonly found in nursing homes, day care One should ask about sexual history in adults

28 SCABIES FOCUS ON THE HANDS IN ADULTS

29 SCABIES AND THE GENITALS

30 SCABIES - TREATMENT Topical permethrin 5% cream (NOT 1%) First line treatment Oral ivermectin can be used if permethrin does not show improvement Wash all bed sheets, pillow cases, cloths on the day of treatment Manufacture recommendation says you only need to treat once, but some physicians prefer to re-treat again in 7 days. All family members really should be treated concurrently Be careful about giving multiple tubes of permethrin to one patient and tell him/her to share it with family. Insurance company may consider this as insurance fraud. If you do decide to treat entire family, give everyone his/her individual prescription

31 MYSTERY CASE

32 MYSTERY CASE

33 HERPES ZOSTER

34 HERPES ZOSTER BACKGROUND Caused by varicella zoster virus, one of eight herpesviruses Patients had chickenpox in childhood, virus goes dormant inside nerves May present with burning sensation, pain, and eventually Grouped vesicles with erythematous base would subsequently present in dermatomal / bandlike configuration Very contagious during this period

35 HERPES ZOSTER DERMATOMES

36 HERPES ZOSTER EXAMPLES

37 HERPES ZOSTER CRANIAL NERVE V

38 HERPES ZOSTER CRANIAL NERVE INVOLVEMENT Hutchinson s Sign Branch CN V1 Involvement

39 HERPES ZOSTER COMPLICATIONS Ramsay Hunt Syndrome, type II Occurs when virus infects the geniculate ganglion of the facial nerve (CN VII) Ipsilateral facial paralysis Ear pain Vesicles in the auditory canal and auricle Herpes zoster ophthalmicus Represents ~15% of all cases Can cause corneal / uveal damage Needs ophthalmology consult

40 HERPES ZOSTER DISSEMINATED

41 HERPES ZOSTER TREATMENT Oral antiviral, either acyclovir or valacyclovir In cases of Ramsay Hunt Syndrome, type II, herpes zoster opthalmicus, and disseminated herpes zoster, IV acyclovir may be needed at least in beginning to ensure no progression of disease during this period given the potential permanent damage in these cases. The shingles vaccine (Zostavax) is recommended for adults age 60 and older, whether they've already had shingles or not. Although the vaccine is approved for people age 50 and older, the Centers for Disease Control and Prevention isn't recommending it until you reach age 60. Patient is contagious when vesicles are present. Patient should avoid contact with pregnant women, children/infants, immunocompromised patients (e.g., HIV, cancer patient). Must keep the area covered until lesion site has completely crusted over When in hospital, please follow CDC guideline on whether it s standard contact precaution +/- airborne precaution

42 MYSTERY CASE

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