Maintaining healthy skin from youth to old age

Transcription

1 Maintaining healthy skin from youth to old age Gillian M. Murphy MD, FRCPI, FRCP Edin Dept Dermatology, National Photobiology Unit, Beaumont and Mater Misericordiae Hospitals, Dublin, Ireland

2 Functions of the skin Barrier to environmental injury Physical injury Ultraviolet radiation Protection of underlying structures Temperature control Complex endocrine effects Complex immunological effects Advertisement of the individual Enables recognition Conveys attractiveness Evidence of health Enables communication by facial expression Pheromone production Sexual maturity Neotony the quest for eternal youth

3

4 Healthy Skin healthy body

5 Kwashiorkor Leprosy

6 Eczema Acne Photoageing Skin cancer

7 Maintainance of barrier function Multiple skin disorders impair skin barrier Eczema (20% children) Dry skin Water loss Itching - scratching Bacterial viral fungal infections Allergies

8 Infantile eczema Genetically influenced Asthma Hay fever Urticaria (hives) Nobody sleeps!

9 Filaggrin mutations Eczema Asthma Peanut allergy Ichthyosis vulgaris

10 Prevention/correction of dry skin Recognise the problem Often a family history of sensitive dry skin Wool intolerance Water intolerance Sweat intolerance Allergic reactions Irritant reactions Bubbles are bad! Grease is good! Use soap-free washing agents Moisturisers trap water in skin after washing Paraffin gel Emulsifying ointment Silcox base/aqueous cream Lotions

11 Allergic contact dermatitis Left hand dermatitis Finger tips Right handed person What is the cause?

12 Allergic contact dermatitis to garlic Cooks Housewives Site of maximum contact Exposure Diagnosis by patch testing Treatment avoid the cause

13 Teenage skin - Adrenarche age 8 Menarche age Puberty in boys: Androgen production Oily skin: face neck trunk Whitehead and blackhead production Avoid oily products Avoid garments inducing sweating Avoid saunas

14 Acne treatment Benzoyl peroxide Topical antibiotics Antiandrogen + oestrogen Oral tetracyclines Erythromycin Trimethoprim 6 month course For severe acne Isotretinoin 4-6 month course Females need 2 forms of contraception Association of suicide attempts with acne and treatment with isotretinoin: retrospective Swedish cohort study BMJ 2010;341:c5812

15 Consequences of sun exposure Sunburn Tanning/Freckling Moles/lentigenes Photodermatoses Skin infections Immunosuppression Skin Cancer Folate depletion Photoageing Ocular effects Vitamin D formation Heliotherapy Appropriate Immune suppression Mood alteration Warmth

16 Skin thickness is very important in determining UVR effects compare the heel with the eyelids

17 Note almost absent stratum corneum on the eyelid

18 UVB

19 Skin colour determines susceptibility Type 1: always burns, never tans Type 2: burns easily, tans poorly Type 3: tans well, sometimes burns Type 4: always tans, sometimes burns Type 5: Asian Type 6: Negroid

20

21 Photoproducts from UVR + DNA HN O O O N H Thymine Dimer CH 3 UVR HN O O N H O N H NH O Cyclobutane pyrimidine dimer

22 rn cells occur after UVR exposure APOPTOSIS: ERROR FREE MECHANISM ERADICATION OF UVR-INDUCED DAMA Retention of p53 mutated cells leads to p patches Lead to Actinic Keratoses And Non-melanoma Skin Cancer

23 DNA Excision Repair 5 3 XPB XPD XPA P62 P44 RPA XPA RPA p34 TTDA 3 5

24 DNA Repair ERCC1 XPA RPA XPF XPB XPD p62 p44 p34 TTDA XPG RFC POL e

25 3MEDs of sun, 24 h after exposure, note sharp margins

26 Action Spectrum for tanning +erythema Burn higher dose of UVA Tan with Lower dose UVA UVB UVA

27 UVB UVB UVA

28

29 Sunbeds, UVA tans before burning

30 Use of sunbeds < 35 years - 75% increase in Melanoma

31 Epidermal Hyperplasia Murphy GM. Quinn DG. Camp RD. Hawk JL. Greaves MW. In-vivo studies of the action spectrum and time course for release of transforming growth factor-alpha by ultraviolet irradiation in man. British Journal of Dermatology. 125(6):566-8, 1991 Dec. UVB but not UVA leads to epidermal hyperplasia A UVB tan is 3-times more protective than the equivalent tan produced by UVA

32

33 Acute effects of UVB on immune functions Murphy GM. Norris PG. Young AR. Corbett MF. Hawk JL. Low-dose ultraviolet-b irradiation depletes human epidermal Langerhans cells. British Journal of Dermatology. 129(6):674-7, 1993 Dec.

34 UV-induced immunosuppression Langerhans cells after UVB LC no 1 MED 1/10 x 10meds 1med 1/10irrad Control

35

36 Polymorphic light eruption Itchy lumpy rash occurring hours after sun exposure 20% of the population Lembo S, Fallon J, O'Kelly P, Murphy GM. Polymorphic light eruption and skin cancer prevalence: is one protective against the other? Br J Dermatol Dec;159(6): Epub 2008 Oct 14. UV Resistant Langerhans cells

37 UV-induced immunosuppression A normal phenomenon Prevents individuals from developing photodermatoses Failure of immunosuppression leads to sun allergies Threshold UV dose for immunosuppression is 50% lower than that for erythema, relying on the SPF was misleading Young et al JID 2000

38 Chronic UVR exposure Photoageing Solar Keratoses Skin Cancer Ocular Damage

39 Photoageing:wrinkling & sagging (smoking makes this worse)

40 UV-induced freckling and dyspigmentation

41 Atrophy and purpura with pseudo-scars

42 Actinic keratoses

43 Basal cell carcinoma Commonest skin cancer BCC:SCC 3:1 Risk Fair skin 12% of males 70 yrs old Sunburn at young age Genetic predisposition Immunosuppression Mutation in Patched gene

44 Squamous cell carcinoma Risk factors UVR exposure Skin Type I and II Males> females Outdoor occupation PUVA Immunosuppression Human papilloma virus infection

45 Malignant melanoma Risk factors Sunburn in young life Skin type I-IV Females > Males 3:1 18/100,000 Living in sunny country Multiple moles Freckles Family history Immunosuppression Use of sunbed PUVA

46 Solar lentigines

47 Effects of UVB & UVA on Skin UVB Sunburn Suntan DPD Epidermal hyperplasia Hyperkeratosis Immunosuppression Dermatoheliosis AKs NMSC, MM? Photo-toxicity/allergy Photodermatoses UVA Tanning IPD DPD Sunburning Immunosuppression Photoageing, Cancer Photo-toxicity/allergy Photodermatoses

48 Behaviour & Clothing determines lifetime UVR dose

49 Photoprotection Polyphenols Pelagic fish Vitamin D

50 Lifestyle and prevention of skin cancer Lifelong photoprotection reducing UVR exposure will prevent skin cancers caused by UVR Balanced diet oily fish, supplemented milk Weight reduction Exercise Alcohol: 1 glass red wine/day No smoking

51 Healthy skin youth-old age Dry skin moisturising shower/baths emollients Oily skin oil free products Lifelong photoprotection Clothing Brimmed hat Sunscreen