Skin Cancer and Desquamation Disorders Keratoderma/ Keratosis

• Definition: a growth of keratin on the skin or mucous membranes stemming from keratinocytes • Types • Punctate Or Palmar plantar keratodermas is on the palms of hands and soles of feet • Actinic keratosis is premalignant caused by cumulative exposure to the sun. may progress slowly to squamous cell CA or a cutaneous horn • Actinic cheilitis is actinic dermatosis of the lip • Seborrheic keratosis is a benign plaque beige to brown in color with a velvety, warty surface • Treatment • Liquid nitrogen or electrodessication and curettage • 5-fluorouracil • Palmarplant Keratodermas can be treated with topical keratolytics Basal cell cancer

• Definition:non melanocytic skin cancer arising from basal cells • Types • Nodular: translucent or pearly papule or nodule • Ulcerating: ulcer with a rolled border and covered with a crust • Sclerosing: White sclerotic patch with ill defined borders • Superficial: erythematous, slightly scaly, thick plaques with pearly border slow growing • Pigmented: thick, hard area of variegated pigmentation. • Diagnosis: via biopsy • Treatment: excision, 5-fluorouracil, radiation therapy, Mohs’ surgery, or imiquimod topical Cutaneous Squamous cell carcinoma

• Definition: skin cancer that begins in squamous cells of the skin • Clinical presentation • Asymptomatic • Sharply demarcated, scaling, or hyperkeratotic macule, papule or plaque. • May have , scaling, erosions, and crusts • typically present as non-healing ulcer in suns exposed areas • Diagnosis: biopsy • Treatment: Excision, Mohs surgery, radiation therapy, electrodessication and curettage, in high risk cases oral 5-FU may be used. Melanoma

• Definition: aggressive form of skin cancer that frequently metastasizes, caused by the malignant transformation of melanocytes • Clinical presentation • Can occur anywhere on the body including eyes and mucous membranes of the genitalia, anus, oral cavity, or nails. • Black or dark brown lesions that may have blue, pink or red component. • Irregular borders with an outward spreading of pigment • Lesions changes size over a relatively short period of time • Lesions can be macular or nodular and include 4 types • Lentigo maligna, superficial spreading (most common), nodular, acral lentiginous (palms, soles, nail beds) • Characterized by ABCDE. Asymmetry, Borders (irregular), Colour variations, Diameter> 6 mm, Elevated Surface • Diagnosis: biopsy and staging workup • Treatment • Surgery, radiation therapy, chemotherapy depending on the stage. Desquamation

• Stevens Johnson Syndrome • Toxic epidermal necrolysis • Urticaria

Clinical presentation • or wheals that are raised with red areas on the skin or mucous membranes caused by the release of histamines, bradykinin, and other vasoactive substances from mast cells and basophils. • Results in small blood vessels to leak and cause intradermal edema. • Wheals may be size of pencil eraser or a large dinner plate and may coalesce into even larger areas. • Lesions are pruritic and may sting or burn. • Acute urticaria • Usually an allergic reaction from food or drugs • Usually self limiting lasting a few minutes to hours • Eliminate allergy exposure, antihistamines, epinephrine if severe • Chronic Urticaria • Cause is often idiopathic but exacerbated by stress • typical antihistamine or H2 blockers( ranitidine) or sometimes both. • Steroids if needed • Physical urticaria • Caused by a reaction to heat or cold, water, exercise or sun exposure • Benadryl, ranitidine or other H1 blocker and avoid exposure if possible Erythema multiforme (EM)

• Definition: Acute Self-limiting type IV hypersensitivity reaction typically associated with certain medications, infections and other triggers • Clinical presentation • Lesions start as macules and become papular • Vesicles and bullae form in the center of the papules • Lesions can be localized to the hands and feet or be generalized • Mucosal lesions (hallmark of EM) are painful and erode • Fever, malaise, weakness • Diagnosis: clinical, biopsy will confirm • Treatment • Avoid/stop trigger • Systemic steroids for severely ill patients • Supportive care Stevens Johnson Syndrome (SJS) Toxic Epidermal Necrolysis(TEN) • Definition • A mucocutaneous blistering reaction most often caused by a severe drug reaction. • Usually associated with sulfonamides, aminopenicillins, quinolones, cephalosporins, tetracyclines, phenobarbital, carbamazepine, phenytoin, valproic acid, oxicam, allopurinol, corticosteroids • SJS is a severe form of erythema multiforme • TEN is a severe form of SJS • life threatening and risks include secondary infection, fluid loss, electrolyte imbalance, kidney failure • Clinical presentation • Fever, photophobia, sore throat, mucosal inflammation, sore mouth • Cutaneous lesions tend to be more concentrated on the trunk at first and are painful and sting • Lesions progress to diffuse erythema, morbilliform lesions, necrotic epidermis, wrinkled surfaces, sheet like loss of epidermis, and raised, flaccid blisters (Nikolsky’s sign) • TEN has a higher fever and more severe epidermal separation and loss • Regrowth of skin takes weeks SJS and TEN

• Diagnosis • Biopsy is diagnostic • Treatment • Stop causative agent • Extensive necrosis should be treated in a burn unit • Wound dressings • Replace fluids and electrolytes aggressively • Treat infections- be careful as antibiotics are the likely cause • Corticosteroids