Dermatology For Boards (And Real Life) Rita Khodosh, MD, PhD Department of Dermatology UC San Francisco Question A 32-year-old farmer comes to your office because of an upper respiratory infection. While he is there he points out a lesion on his forearm that he first noted approximately 1 year ago. It is a 1-cm asymmetric nodule with an irregular border and variations in color from black to blue. The patient says that it itches and has been enlarging for the past 2 months. He says he is so busy that he is not sure when he can return to have it taken care of. Suspicious Pigmented Lesion Question In such cases the best approach would be to . perform a punch biopsy and have the patient return if the biopsy indicates pathology . perform a shave biopsy, with a recheck in 2 months for signs of recurrence . use electrocautery to destroy the lesion and the surrounding tissue . perform an elliptical excision as soon as possible . freeze the site with liquid nitrogen Melanoma • Destruction (cryotherapy, electrodessication, currettage) is NEVER appropriate • Best way to biopsy a suspicious pigmented lesion is an EXCISIONAL BIOPSY (elliptical, punch, or saucerization) • To properly stage and plan treatment of a Melanoma one needs to know it’s greatest DEPTH Melanoma Margins Melanoma Sentinel Lymph Node Biopsy Sentinel Lymph Node Biopsy is offered for melanomas : • >1mm Breslow Depth • <1mm with ulceration, increased mitotic rate and certain adverse features Melanoma Biopsy Real Life Melanoma Biopsy Real Life • Sometimes, a partial biopsy is okay… • Don’t let the perfect be the enemy of the good enough • If you are not comfortable performing a biopsy, make sure the patient is seen without delay by a provider who is (Dermatology, ENT, Plastics, General surgery, etc) Question A 72-year-old white farmer presents to your office with an enlarging raised lesion on the dorsum of his hand. It appears to be arising from an area of actinic keratosis. Erythematous scaly papule on dorsal hand Question Due to its location you suspect which one of the following? A) Basal cell carcinoma B) Keratoacanthoma C) Malignant melanoma D) Psoriatic plaque E) Squamous cell carcinoma Cutaneous Squamous Cell Carcinoma • Most associated with chronic sun exposure (cumulative effect) • Scalp, face, dorsal hands, neck • Other risk factors for development of SCC: - burn - chronic ulcer - radiation - HPV (anogenital) - immunosuppression Cutaneous Squamous Cell Carcinoma Higher risk for recurrence and metastasis include: • Size >2cm • Depth (>4cm) • Perineural invasion (Painful lesion) • Immunosuppression • Location on the ear, lip, anogenital Keratoacanthoma • A type of SCC? • Rapid growth • Nodule with keratinous core • Can involute on its own • Usually treated • Excision is best Question You note a skin lesion on the nose of a 70- year-old male painter during a visit for a routine upper respiratory infection. He tells you that the lesion "sometimes bleeds a little." It is a raised, smooth, pale, pearly, shiny papule with prominent telangiectasia evident across its surface. Shiny papule with prominent telangiectasia Question This lesion is most likely A) a spider angioma B) a basal cell carcinoma C) an atypical melanoma D) actinic keratosis E) sebaceous hyperplasia Basal Cell Carcinoma • Most common type of skin cancer • Sun-exposed areas (face, neck) • Fair skin, sunburn history • Rarely metastasize, some can be locally invasive and aggressive • Diagnosed with shave or punch biopsy (punch if you are worried about more infiltrative BCC) BCC Treatment • Face (especially mid face)—Mohs procedure • Excision • Electrodessication and Curettage (not on face or neck, not for infiltrative BCC) • Imiquimod or 5FU (Superficial BCC) • Radiation if cannot tolerate surgery (usually elderly patients) • Vismodegib--hedgehog pathway inhibitor (metastatic or inoperable BCC) Question Which one of the following statements is consistent with current U.S. Preventive Services Task Force recommendations for skin cancer screening for the adult general population with no history of premalignant or malignant lesions? Skin Cancer Screening A) Whole-body examination should be conducted by a primary care provider every 3 years B) Whole-body patient self-examination should be performed every 6 months C) Benefits from screening have been established only for high-risk patients D) The evidence is currently insufficient to determine whether early detection reduces mortality and morbidity from skin cancer E) The harms of detection and early treatment outweigh the benefits Skin Cancer Screening • The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of visual skin examination by a clinician to screen for skin cancer in adults I screen • patients with history of skin cancer • patients with fair skin over 50 (especially men) who have evidence of significant sun damage or patients with other risk factors for NMSC • patient with increased melanoma risk UV radiation causes melanoma What about indoor tanning? Question A 55 year old white female presents with redness at the scar from a lumpectomy performed for stage I cancer of her right breast 4 months ago. The patient has completed radiation treatments to the breast. She is afebrile and there is no axillary adenopathy. There is no wound drainage, crepitance, or bullous lesions. Question Which one of the following organisms would be the most likely cause of cellulitis in this patient? A) Non group A Streptococcus B) Pneumococcus (Strep pneumoniae) C) Clostridium perfringens D) Escherichia coli E) Pasteurella multocida Causes of Cellulitis • Beta-hemolytic Streptococci (most often Group A) • Staph Aureus • Non-purulent cellulitis—cover for Strep and MSSA (Cephalexin) • Purulent cellulitis—cover for MRSA (Bactrim DS, Doxycycline, Clindamycin) and culture • Abscess—INCISION AND DRAINAGE Unless complicated (cellulitis, immunocompromised, fever, etc) Other Staph and Strep infections Impetigo • S. aureus more common • Beta-hemolytic Strep less • Localized cases can be treated with mupriocin • More generalized with oral antibiotics (Cephalexin or Dicloxacillin) for 7 days • Culture (if MRSA, tx with doxycycline, clinda or trimethoprim-sulfamethoxazole) Other Staph Infections Acute Paronychia • No abscess—warm soaks and topical mupirocin • Abscess—drainage, soaks and mupirocin • Culture • Oral anti-staph antibiotics for 7 days for more severe cases Chronic Paronychia - Eczematous process - Minimize irritation and damage - Treat with topical steroids first - Candidal infection is secondary Not to be confused with Herpetic Whitlow • Grouped vesicles on an erythematous base • HSV 1 or 2 infection of finger from oral inoculation (most often in children, healthcare workers) • Painful, can have fever and regional lymphadenopathy • DFA or viral culture to confirm • Do not need to treat, self-limited Herpes Zoster Reactivation of latent VZV Treatment of Herpes Zoster • Antiviral therapy with acyclovir, valacyclovir, famciclovir • Best when given within first 72 hours • Treat after 72 hrs if still getting new lesions, immunosuppressed, pregnant • Treat pain! • Warn about contact with pregnant women, unvaccinated babies, immunocompromised • Treat with antivirals AND call ophthalmology if Herpes Zoster Ophthalmicus Question Imiquimod (Aldara) is approved by the FDA for treatment of which one of the following conditions? A) External anogenital warts B) Plantar warts C) Flat warts D) Periungual warts E) Molluscum contagiosum External anogenital warts Imiquimod • A toll-like receptor-7 agonist • Enhances both the innate and acquired immune response • FDA approved for treatment of external anogenital warts • Sometimes used for other types of warts (flat warts > verruca vulgaris), but it does not work as well • Sometimes used for Molluscum, but cantharidin and cryotherapy work better Question • An otherwise healthy 37-year-old male presents to your office with a 2-week history of redness and slight irritation in his groin. On examination a tender erythematous plaque with mild scaling is seen in his right crural fold. The area fluoresces coral-red under a Wood’s light. Question Which one of the following would be the most appropriate treatment at this time? A) Amoxicillin B) Erythromycin C) Ketoconazole D) Nystatin (Mycostatin) E) Triamcinolone (Kenalog) Erythrasma Erythrasma • Erythrasma is caused by C. minutissimum, a component of the normal skin flora • Overgrowth in stratum corneum occurs under conditions of occlusion and moisture • Topical erythromycin and clindamycin are first line • Oral clarithromycin or erythromycin for extensive disease • Topical imidazole antifungals (econazole) also work Other Groin Rashes Candida • Moist • beefy red • Satellite pustules • Keep area dry • Nystatin • Imidazole antifungals Other Groin Rashes Tinea Cruris • Scaly plaque • Serpiginous scaly border - Topical Imidazoles or Allylamines (Terbinafine) - Oral Terbinafine for extensive tinea corporis Question A 69-year-old female sees you for an annual examination. She asks you to look at her toes, and you note a fungal infection in five toenails. She says the condition is painful and limits her ability to complete her morning walks. She asks for treatment that will allow her to resume her daily walks as soon as possible. Her only other medical problem is allergic rhinitis which is well controlled. Onychomycosis Question Which one of the following would be the most appropriate treatment for this patient? A) Oral griseofulvin ultramicrosize