Dermatology¶
Lauren Waskowicz
| Primary Lesion | Secondary Lesion |
|---|---|
| Flat: Macule (<5mm) versus patch (>4mm) Raised: Papule (<5mm) versus plaque (>4mm) Fluid Filled: Vesicle (<5mm) versus Bullae (>4mm) versus Pustule (pus-filled) Nodule - firm, thicker, deeper, 1 and 2 cm in diameter. {br> Non Blanching: Petechial (<4mm) versus purpura (4-10mm) |
Excoriations: “Excavations” dug into skin secondary to scratching Lichenification: Roughing of the skin with accentuation of skin markings Scale: Flakes of stratum corneum Crust: Rough surface, dried serum, blood, bacteria, and cellular debris Ulceration: Loss of epidermis and dermis Erosion: Loss of the epidermis |
Corticosteroids: General Principles¶
- Main side effects ➔ skin atrophy
- Face and intertriginous areas ➔ low potency steroids ONLY
- High potency steroids should be limited to 3 weeks of use
- Optimal absorption if applied after bathing (hydration promotes steroid penetration)
- Ointments - most potent due to occlusive effect, good for thick, hyperkeratotic lesions and areas of smooth, NON-hairy skin. Avoid hairy and intertriginous areas (can cause skin maceration and folliculitis)
- Creams - more cosmetically appearing and well tolerated. Less potent than ointments
- Lotions - useful in hairy and intertriginous areas. Less potent than creams
| Low Potency | Medium Potency | High Potency | Very High Potency |
|---|---|---|---|
| Desonide 0.05% (cream, lotion, ointment) | Triamcinolone (Kenalog) 0.025% (ointment, cream) | Triamcinolone (Kenalog) 0.1% (ointment, cream) | Betamethasone dipropionate 0.05% (ointment, cream, lotion) |
| Hydrocortisone acetate (OTC) | Hydrocortisone valerate 0.2% (ointment, cream) | Triamcinolone (Kenalog) 0.5% (ointment, cream) | Clobetasol 0.05% (cream, ointment, lotion, gel, foam) |
Common Rashes¶
| Condition (link to pictures) | Description/Symptoms | Management |
|---|---|---|
| Morbilliform Drug Rash (Link to Pictures) |
- Erythematous macules ➔ confluent papules - Trunk ➔ extremities, symmetric - Most common precipitants = antibiotics (beta-lactam antibiotics, sulfa drugs), allopurinol, AEDs, NSAIDs - Sx: Pruritus, low grade fever |
- Discontinue offending agent - Topical Corticosteroids, wet wraps - Antihistamines - If eosinophilia, kidney/liver dysfunction, mucous membrane lesions or painful/dusky lesions, consider alternative diagnosis (DRESS, AGEP, SJS/TEN) |
| Erythema Multiforme (Link to Pictures) |
- Abrupt onset of papular “target” lesions in symmetrical acrofacial sites, +/-mucosal involvement - Usually precipitated by HSV - Sx: Lesions can be painful, pruritic or swollen - Systemic symptoms likely attributed to inciting infection (HSV, CMV, EBV, flu, COVID etc) |
- Oral antihistamines and/or topical steroids for itch - Treat precipitating infections (HSV tx does not alter course of single episode, can help prevent future inf) - Stop offending medications - If recurrent, derm referral for prolonged antiviral course |
| Zoster (Link to Pictures) |
- Reactivation of VZV leading to blistering, painful rash in dermatomal distribution - Rash can last 3-4 weeks - Sx: Painful pustular lesions with systemic symptoms including fever, headache and lymphadenopathy |
- Best treatment is prevention (shingles vaccine in adults >50) - Valacyclovir 1000 mg TID if symptoms started w/in 72 hours and patient has new lesions) for 7 days OR acyclovir 800 mg 5x daily for 7 days - Can be complicated by post-herpetic neuralgia, manage w/ early antiviral treatment, topical capsaicin, TCAs, gabapentin/pregabalin |
| Seborrheic Dermatitis (Link to Pictures) |
- Inflammatory response to malassezia yeasts - Characterized by erythematous w/ yellowish and greasy scale of scalp, face, upper trunk, intertriginous areas - Can be associated with HIV, parkinson's disease and use of neuroleptic medications - Chronic, relapsing (mildest form = dandruff) - Sx: Usually non-pruritic |
- Mild symptoms + isolated to scalp (i.e. dandruff) ➔ antifungal shampoo (Rx: ketoconazole 2%, OTC: selenium sulfide 2.5%) - Moderate/severe symptoms w/ scale, inflammation and pruritus of the scalp➔ antifungal shampoo + 2 week high potency topical corticosteroid followed by 2x weekly use of high potency topical steroids |
| *Tinea Pedis ('athlete's foot') (Link to Pictures) Tinea Corporis ('body ringworm') (Link to Pictures) Tinea Capitis ('scalp ringworm') (Link to Pictures) Tinea Cruris ('jock itch') (Link to Pictures) Onychomycosis ('fungal nail infection') (Link to Pictures) |
- Presentation depends on location - Pedis: itchy erosions/scales between toes, hyperkeratosis/scale covering soles/sides of feet, vesiculobullous blisters of inner aspect of foot - Corporis: solitary circular red patch with raised scaly leading edge, forms ring-shape with hypopigmentation - Capitis: partial hair loss, +/- erythema, +/- pustular lesions - Curis: erythematous bilateral but asymmetrical rash with raised border and central clearing - Onychomycosis - Perform KOH preparation if possible to confirm diagnosis - Sx: Can be itchy and erythematous or asymptomatic |
- Treat all sources of tinea to prevent re-infection. - Nystatin IS NOT effective treatment - Pedis/Corporis/Cruris: if localized infection ok for topical antifungals (clotrimazole 1% BID until clinical resolution 1-4 weeks) - Capitis: Oral griseofulvin (500-1000 mg daily for 4-6 weeks) or oral terbinafine (250 mg once daily for 4 to 6 weeks) - Onychomycosis: Oral terbinafine (250 mg once daily for 6 weeks (fingernail) or 12 weeks (toenail)), topical therapy (efinaconazole, amorolfine, ciclopirox) |
| Paronychia (Link to Pictures) |
- Inflammation of the skin around a finger or toenail - Can be associated with felon (painful abscess at the base of the toe/nail) or herpetic whitlow (viral cutaneous infection caused by HSV) - Usually due to staph/strep or pseudomonas - Sx: Pain at the site of the infection, can develop systemic infection leading to fever/chills/myalgias |
- If no abscess formation, can manage with soaking affected digit in warm water and antiseptics (chlorhexidine soaks TID) with mupirocin applied after soaking - If abscess present ➔ I& D culture - Antibiotics indicated if symptoms not improving after I&D or systemic symptoms (dicloxacillin 250-500 mg QID, cephalexin 500 mg QID) for 5 day duration - If risk factors for MRSA ➔ Bactrim 1-2 DS tablets BID - If oral flora present ➔ augmentin 875/125 mg BID |
| HSV (Link to Pictures) |
- Present as clusters of 2-3 mm umbilicated clear or hemorrhagic vesicles persisting for 5-10 days usually preceded by localized tingling/burning - Type 1 most commonly associated with oral lesions, Type 2 w/ genital lesions - Diagnose with viral culture of swab from vesicle or serologic testing (may be positive and not causing symptoms) - Sx: Lesions are painful, can be associated with mild malaise and fever |
- No cure, following initial infection immunity develops but does not prevent against further attacks - Tx w/ topical therapy for mild infections - For initial infection: Valacyclovir 500 mg BID 3-5 d, acyclovir 200 mg 5x/d for 5 days - For recurrent infections: oral valacyclovir 500 mg BID for 3 days or 1 g daily for 5 days OR Acyclovir 800 mg BID for 5 days - For suppressive therapy: oral valacyclovir 500 mg or 1 g daily |
| Candida - Balanitis (Link to Pictures) -Intertrigo (Link to Pictures) |
- Balanitis: inflammatory versus infectious condition of the glans penis. Most commonly infectious cause (candida versus dermatophytosis) - Sx: penile soreness, dysuria, itchiness, bleeding and erythema of the glans - Candidal balanitis associated with white, curd-like exudate - Intertrigo: erythematous/macerated plaques with peripheral scaling, often associated with superficial satellite papules or pustules - Affects skin below breasts or under abdomen, armpits, groin and web spaces between fingers/toes |
- Balanitis: attention to genital hygiene with retraction of foreskin and cleansing for prevention/therapy - Clotrimazole cream BID for 7-14 days - Intertrigo: Prevention with moisture-free skin, can use talcum powder to assist in intertriginous areas - Topical antifungal agents (clotrimazole 1% cream BID for 4 weeks, 1% ointment BID for 2 weeks) - Oral fluconazole or itraconazole for severe, generalized and/or refractory cases |
| Pityriasis versicolor (Link to Pictures) Pityriasis Rosacea (Link to Pictures) |
- Pityriasis versicolor: Superficial fungal skin infection caused by Malassezia - Hypo/hyperpigmented or erythematous macules/patches or thin plaques most common on upper trunk, upper extremities -Sx: usually asymptomatic - Pityriasis rosacea: Self-limiting rash (6-10 weeks) characterized by large circular/oval “herald patch” found on chest/abdomen or back followed by small scaly oval red patches on back and chest (sometimes described in Christmas tree pattern) - Sx: vary from mild to severe itching. ⅔ of patients have flu-like symptoms prior to rash onset |
- Pityriasis versicolor: Topical antifungal treatment with ketoconazole 2% shampoo (Daily for 3 days), selenium sulfide 2.25% shampoo or terbinafine 1% cream - Pityriasis rosacea: Self-limiting disease therefore treatment is symptom management - Apply daily moisturizing creams, avoid drying soaps - Can trial medium potency topical steroids and oral antihistamines |
| Atopic Dermatitis (Eczema) (Link to Pictures) |
- Lesions are pruritic, erythematous, +/- weeping/exudative, +/- blistering. Can become lichenified and scaly with fissuring over time. - Most commonly occurs on neck, hands and flexural surfaces in adults - Associated with atopic triad (asthma, eczema, and allergies) |
- Avoid triggers (fabrics, chemicals, humidity, and dryness, foods) - Daily skin hydration w/ emollients ointments > creams (take into consideration patient tolerability) - Topical corticosteroids: Mild disease - hydrocortisone 2.5% BID until 3-5 d after skin clearance. Moderate disease - triamcinolone 0.1% or 0.025% Clobetasol cream for up to two weeks followed by mild steroids - Skin and face folds treatment: Desonide 0.05% OR topical calcineurin inhibitors (tacrolimus 0.1% BID, discontinue when symptoms cleared) |
| Psoriasis (Link to Pictures) |
- Clearly defined red and scaly plaques, symmetrically distributed - Most common locations are scalp, elbows, knees - Sx: Pruritus is common but mostly mild, treating can lead to hyper/hypopigmented plaques that fade over time |
- Limited disease ➔topical corticosteroids and emollients
- Scalp/external ear canal: potent corticosteroids - clobetasol propionate 0.05% BID until lesions clear - Face/intertriginous: low-potency OTC hydrocortisone 1% or prescription-strength 2.5% BID until lesions clear - Thick plaques on extensor surfaces: clobetasol propionate 0.05% BID until lesions clear - Moderate to Severe ➔ Phototherapy + topical steroids/emollients, before systemic agents (e.g. MTX) |
| Acne (Link to Pictures) |
- Open and closed comedones, noninflammatory versus inflamed papules/pustule - Severe cases involve nodules, pseudocysts with scarring |
- Mild acne: daily topical retinoid (tretinoin) + benzoyl peroxide (if papulopustular lesions present) - Moderate/severe: Isotretinoin (cumulative dose of 120-150 mg/kg) - If isotretinoin is contraindicated, consider oral doxy (100 mg daily for 3-4 m) OR OCP OR spironolactone (25 to 50 mg/day in 1 to 2 divided doses, titrate based on response/tolerability) |
| Allergic Contact Dermatitis (Link to Pictures) |
- Type of eczema caused by allergic reaction to allergen (type IV hypersensitivity), usually 48-72 hrs after exposure - Symptoms include erythematous, indurated pruritic plaques, +/- edema, +/- blistering, +/- scale - Consider triggers such as nickel, fragrances/perfumes, work exposures, poison ivy |
- Determine allergen, if not identified easily, can have comprehensive patch testing - Acute/localized rash on hands/feet or nonflexural areas ➔ high potency topical corticosteroids BID until resolution (up to 4 weeks) then taper over 2 weeks - Acute/localized rash on face/flexural areas ➔ medium/low potency topical steroids BID for 1-2 weeks then taper over 2 weeks OR topical tacrolimus 0.1% until resolution then taper |
| Stasis Dermatitis (Link to Pictures) |
- Caused by venous hypertension resulting from dysfunction of venous valves, obstruction to venous flow - Sx: include edema, inflammatory skin changes, pruritus, tenderness, ulceration, varicosity and hyperpigmentation (hemosiderin deposition) |
- Compression therapy with bandaging systems or stockings, elevation of legs, regular exercise other than standing - Emollient (petroleum jelly) application for dryness/pruritus - Acute disease w/ erythema, pruritus, vesiculation, and oozing ➔ consider high/mid-potency topical corticosteroids BID for 1-2 weeks - Referral to vascular if persistent symptoms |
| Rosacea (Link to Pictures) |
- Chronic inflammatory condition affecting central face, usually appears between 30-60 yo - Persistent facial redness, telangiectasia, thickening of skin and possible development of inflammatory papules/pustules. - Pathophysiology multifactorial, includes genetic susceptibility, immune dysregulation, neurocutaneous triggers (sunlight, temperature, exercise, spicy foods, alcohol, stress, tobacco) |
- Learn/avoid triggers (alcohol, tobacco),use gentle skin care products, and sun protection - Consider pharmacological intervention with topical brimonidine, laser or intense pulsed light therapy - If complicated by papular/pustular disease, consider topical metronidazole 0.75% gel for mild disease, and oral tetracycline/doxycycline for moderate to severe disease |