Dermatology “Doc, I Have This Rash…”

1. Dermatology“Doc, I Have This Rash…” Joseph S. Baler M.D. September 7, 2013

3. Guttate Psoriasis • Small pink papules with scale. • Scalp, face, trunk, and ext.

4. Guttate Psoriasis • 2-3 wks post group A strep. • Personal or family h/o psoriasis. • May be initial psoriatic event. • Post sunburn. • Viral URI.

5. Guttate Psoriasis • Look for Strep. • Pen VK 500mg BID. • Topical mid potency steroids such as TAC 0.1% cream. • NBUVB , Sunlight. • Do not use Prednisone!

6. Photodermatitis

7. Phototoxicity Photoallergy • Sunburn reaction, erythema, edema. • Direct tissue injury • Occurs after first exposure. • Onset minutes to hours. • Large dose of agent needed for eruption. • Pruritic, eczematous lesions. • Type IV delayed hypersensitivity. • Does not occur after first exposure. • Onset 24-48 hours. • Small dose of agent.

8. Phototoxicity Photoallergic

9. Phototoxic agents • Systemic: Tetracyclines, Phenothiazines, Thiazides, Furosemide, Sulfonylureas. • Topical: Furocoumarins: lime, lemon, celery, tar.

10. Photosensitivity/Doxycycline

11. Photoallergic agents • Systemic: Quinolones,NSAIDs, sulfonamides. • Topical: Fragrances.

12. Photocontact/Allergic Contact Dermatitis

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14. At beach. • Having a refreshing drink with a twist of lime.

15. Phytophotodermatitis • Limes have psoralens containing compounds that are phototoxic. • Oil of Bergamot

16. Phytophotodermatitis • Initial onset erythema or blisters after contact and sun exposure. May be absent. • 48-72 hrs later hyperpigmentation at sites of contact. • May persist up to 4-6 weeks

17. Phytophotodermatitis • Biting into lemon • Squeezing limes

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20. Allergic Contact Dermatitis-Mangos • Mango skins have urushiol which is same as poison ivy • Oil from skin of mango drips onto skin creating contact dermatitis

21. Poison Ivy • Leaves and vine can cause rashes • Any season • Sensitivity varies from person to person • Three leaflets

23. Poison Ivy • Look for linear blisters or erythema • Very pruritic • Blister fluid is not contagious

24. Poison Ivy • New areas may develop over time due to small areas of chemical contact taking longer to react.

27. Resin from plant called urushiol can oxidize and turn black on the skin which is called a “black lacquer spot”

28. Treatment • Ultra potent topical steroids if a localized area such as clobetasol propionate 0.05% • Systemic steroids often needed • Medrol dose pack too little, and too short • Prednisone 40-60mg with a slow taper over 12-18 days, maybe longer if reactivation

29. Ivy Block etc. may help prevent the oils from the plant getting to the skin by acting as a barrier which you apply as a lotion prior to potential contact • Wash all clothes, tools, shoes, and gloves after contact since resin may last for years even when air dried.

32. Swimmer’s Itch (clam digger’s itch) Sea Bather’s Eruption

33. Swimmer’ Itch Sea Bather’s Erupt. • Water: fresh or salt • Body part: uncovered • Locale: North US and Canada • Cause: cercarial forms of nonhuman schistosomes(snails) • Water: salt • Body part: covered • Locale: Florida and Cuba • Cause: larval forms of marine coelenterates (sea anemone, jellyfish)

34. Treatment/Prevention • Swimmer’s itch: symptomatic Rx for itch. Vigorous towel drying may prevent penetration of the cercariae • Sea Bather’s eruption: symptomatic Rx for itch. Remove swimwear before shower since fresh water may cause discharge of nematocysts. Heat dry swimwear

35. Swimmer’s Itch (clam digger’s itch) Sea Bather’s Eruption

36. Tinea Versicolor

37. Tinea Versicolor • Malasseziafurfur • Normal cutaneous flora • 2-8% US population • Warm, humid enviroment • Very common in tropical regions of world • Immunosupression, Cushings disease

38. Hyper and hypopigmented macules with fine scale • Hypopigmentation caused by tyrosinase inhibition • Hyperpigmentation caused by enlarged melanosomes

40. KOH: short hyphae and spores “spaghetti and meatballs”

41. Tinea Versicolor - Treatment • Topical anti-fungals • Selenium sulfide 2.5% lotion • Oral ketoconazole 400mg single dose, repeat in 1 week • Fluconazole 200-400mg weekly 2-4 weeks • Itraconazole 200mg QD x 7 days

42. Pityriasis Rosea

43. Pityriasis Rosea • Pruritic, oval, salmon-colored macules with collarettescale • Herald patch on neck or trunk, then 1-2 wks later smaller lesions • Lasts approx. 12 weeks

44. Pityriasis Rosea • Follows skin creases • Can have atypical cases which are more papular, vesicular, or widespread

47. Pityriasis Rosea • Probable viral etiology, but no definitive data • Clusters during spring common • Not contagious

48. PR- Treatment • Symptomatic for itch: antihistamines, topical steroids • UVB, sunlight helpful

49. Perioral Dermatitis • Acneiform lesions. • Erythema and scale. • Common in women. • Etiology unclear, but topical steroid use often the cause.

50. Perioral Dermatitis • Perioral and perinasal most common. • Occasional periocular.