Outline Dermatology Pearls for the Primary Care Practitioner Part 2 - PDF document

Outline Dermatology Pearls for the Primary Care Practitioner‐ Part 2 • Chronic urticaria • Onychomycosis Lindy P. Fox, MD • The red leg Professor of Clinical Dermatology • Grovers disease Director, Hospital Consultation Service • Pearls to know Department of Dermatology University of California, San Francisco lindy.fox@ucsf.edu I have no conflicts of interest to disclose I may be discussing off-label use of medications 1 2 • 36 yoF complains of 2 mo of urticaria • Lesions last < 24 hours, itchy • Failed loratadine 10 mg daily Chronic Urticaria 3

Chronic Urticaria Chronic Urticaria‐ Workup • History and physical guides workup • Urticaria, with or without angioedema > 6 • Labs to check weeks – CBC with differential – Lesions last < 24 hours, itch, completely resolve – ESR, CRP • Divided into chronic spontaneous (66‐93%) – TSH and thyroid autoantibodies or chronic inducible – Liver function tests • Natural history‐ 2‐5 years – CU Index (Fc‐εRIα Ab or Ab to IgE) – Maybe tryptase for severe, chronic recalcitrant disease – > 5 yrs in 20% patients – 13% relapse rate – Maybe look for bullous pemphigoid in an older patient • Etiology • Provocation for inducible urticaria – 30 ‐50 % ‐ IgG autoAb to IgE or FcεRIα – Remainder, unclear Eur J Dermatol 2016 Clin Transl Allergy 2017. 7(1): 1‐10 Allergy Asthma Immunol Res. 2016;8(5):396‐403 Eur J Dermatol 2016 Clin Transl Allergy 2017. 7(1): 1‐10 J Allergey Clin Immunol Pract. 2017. Sept 6. S2213‐2198 Chronic Spontaneous Urticaria‐ Treatment First line H1 antihistamines‐ 2 nd generation What does my “second line” look like? <40% respond to standard dose H1 blockade Avoid triggers (NSAIDS, ASA) Can increase to up to 4X standard dose 60% chance of response Second line • Fexofenadine 360 mg am, 180 mg noon, 360 mg pm High dose 2 nd generation AH • Cetirizine 10 mg BID Add another 2 nd generation AH • Hydroxyzine 25 mg QHS 1 st gen H1 antihistamine QHS +/‐ H2 antagonist • +/‐ Monteleukast 10 mg QD +/‐ Leukotriene antagonist • +/‐ Ranitidine 300 mg QD Third line Omalizumab • Give epipens (3) Cyclosporine Dapsone Sulfasalazine Hydroxychloroquine J Allergy Clin Immunol 2014. 133(3):914‐5 BJD 2016. 175:1134–52 • When time to taper, take off 1 pill per week Mycophenolate mofetil Clin Transl Allergy 2017. 7(1): 1‐10 TNFα antagonists Allergy Asthma Immunol Res. 2016;8(5):396‐403 Eur J Dermatol 2016 (epub ahead of print) Anti CD20 Ab (rituximab) Allergy Asthma Immunol Res. 2017 November;9(6):477‐482. Allergy 2018. Jan 15. epub ahead of print

CSU‐ when to refer • Atypical lesion morphology or symptoms – > 24 hours, central duskiness/purpura – Asymptomatic or burn >> itch Onychomycosis • Minimal response to medications – High dose H1 nonsedating antihistamines – H1 sedating antihistamines • Associated symptoms – Fever, fatigue, mylagias, arthralgias • Elevated ESR/CRP 10 Onychomycosis Onychomycosis • Infection of the nail plate by fungus • Vast majority are due to dermatophytes, especially Trichophyton rubrum • Very common • Increases with age • Half of nail dystrophies are onychomycosis • This means 50% of nail dystrophies are NOT fungal 11 12

Onychomycosis Onychomycosis Diagnosis • KOH is the best test, as it is cheap, accurate if positive, and rapid; Positive 59% • If KOH is negative, perform a fungal culture • Frequent contaminant overgrowth • 53% positive • Nail clipping • Send to pathology lab to be sectioned and stained with special stains for fungus • Accurate (54% positive), rapid (<7d), written report • Downside: Cost (>$100) 13 14 Onychomycosis Onychomycosis: Local Treatment Interpreting Nail Cultures • Laser‐ insufficient data that it works • Any growth of T. rubrum is significant • Topical Therapy: • Contaminants • Ciclopirox (Penlac) 8% Lacquer: – Not considered relevant unless grown twice • Cure rates 30% to 35% for mild to moderate onychomycosis from independent samples AND no (20% to 65% involvement) dermatophyte is cultured • Clinical response about 65% – Relevant contaminants: • Efinaconazole (Jublia) 10%* • C. albicans • Daily for 48 weeks • Scopulariopsis brevicaulis • Complete or almost complete cure (completely clear nail)‐ 26% • • Fusarium Mycologic cure (neg KOH and neg fungal cx)‐ 55% • • Scytalidium (Carribean, Japan, Europe) Tavaborole (Kerydin) 5%* – Especially in immunosuppressed patients • Daily for 48 weeks • Complete or almost complete cure (completely clear nail)‐ 15‐17% • Mycologic cure (neg KOH and neg fungal cx)‐ 31‐36% 15 16 *Data from pharma website

Onychomycosis Onychomycosis: Systemic Treatment Assessing Treatment Efficacy • • Nail growth Itraconazole: – At 2 to 3 months nail begins to grow out – 200 mg/d for 3 months – Continues for 12 months – 400 mg/d for one week per month for 4 months • Repeat KOH/culture at 4-6 months • Terbinafine: 250mg po QD – If culture still positive, treatment will likely fail – Fingernails: 6 weeks – KOH may still be positive (dead dermatophytes) – Toenails: 12 weeks • Failures • Check LFTs at 6 weeks – Pulse dosing – Terbinafine resistance • 500 mg daily for one week monthly for 3 months – Non-dermatophyte molds – Efficacy: 35% complete cures; 60% clinical cures – Dermatophytoma 17 18 The red leg: Cellulitis and its (common) mimics • Cellulitis/erysipelas • Stasis dermatitis • Contact dermatitis 19

Cellulitis • Infection of the dermis • Gp A beta hemolytic strep and Staph aureus • Rapidly spreading • Erythematous, tender plaque, not fluctuant • Patient often toxic • WBC, LAD, streaking • Rarely bilateral • Treat tinea pedis

Stasis Dermatitis Contact Dermatitis • Itch (no pain) • Often bilateral, L>R • Patient is non‐toxic • Itchy and/or painful • Red, hot, swollen leg • Erythema and • No fever, elevated WBC, edema can be severe LAD, streaking • Look for sharp cutoff • Look for: varicosities, • Treat with topical edema, venous ulceration, hemosiderin deposition steroids • Superimposed contact dermatitis common Contact Dermatitis • Common causes – Applied antibiotics (Neomycin, Bacitracin) – Topical anesthetics Grover’s Disease (benzocaine) – Other (Vitamin E, topical diphenhydramine) • Avoid topical antibiotics to leg ulcers – Metronidazole OK (prevents odor) 28

Grovers Disease (transient acantholytic dermatosis) • Sudden eruption of papules, papulovesicles; often crusted • Mid chest and back • Itchy • Middle aged to older men • Etiology unknown‐ heat, sweating • Risk factors: hospitalized, febrile, sun damage • Transient • Treatment: topical steroids (triamcinolone 0.1% cream); get patient to move around Pearls to know

Pustular Psoriasis • Pustular and erythrodermic variants of psoriasis • Can be life‐threatening • Most common in patients who carry a diagnosis of psoriasis who have been given systemic steroids and then tapered • High cardiac output state with risk of high output failure • Electrolyte imbalance (Ca 2+ ), respiratory distress, temperature dysregulation • Best treated with hospitalization and cyclosporine or acitretin 33 34 35 36

Lotrisone Tinea Incognito • Combination of betamethasone plus clotrimazole – Weak antifungal + superpotent steroid • Inadequate to kill fungus and may cause complications (striae, fungal folliculitis) • Dermatologists rarely use it • Rarely indicated 37 38 Case • 67M underwent an elective saphenous vein phlebectomy for asymptomatic varicosities • 4d post op, he develops erythema around the wound. • Ulceration continues to expand despite multiple debridements and broad spectrum antibiotics. • Wound cultures are negative • 3 weeks later, he is transferred to UCSF and a dermatology consultation is called • Tmax 104, WBC 22

Pyoderma Gangrenosum • Rapidly progressive (days) ulcerative process • Begins as a small pustule which breaks down forming an ulcer • Undermined violaceous border • Expands by small peripheral satellite ulcerations which merge with the central larger ulcer • Occur anywhere on body • Triggered by trauma (pathergy) (surgical debridement, attempts to graft) Pyoderma Gangrenosum Pyoderma Gangrenosum • 50% have no • Workup underlying cause – Skin biopsy for H&E and culture • Associations (50%): – Rheumatoid factor – Inflammatory bowel – SPEP/UPEP disease (1.5%-5% of – ANCA (ulcers of Granulomatosis with IBD patients get PG) Polynagiitis can mimic PG) – Rheumatoid arthritis – Seronegative arthritis – Colonscopy (r/o IBD) – Hematologic – Peripheral smear, Bone marrow biopsy (r/o abnormalities (AML) AML)