Dermatology

Lauren Waskowicz


Primary Lesion

Secondary Lesion

Flat: Macule (<5mm) versus patch (>4mm)

Raised: Papule (<5mm) versus plaque (>4mm)

Fluid Filled: Vesicule (<5mm) versus Bullae (>4mm) versus Pustule (pus-filled)

Nodule - firm, thicker, deeper, 1 and 2 cm in diameter.

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)

Hydrocortisone acetate (OTC)

Triamcinolone (Kenalog) 0.1% (ointment, cream)

Hydrocortisone valerate 0.2% (ointment, cream)

Betamethasone dipropionate 0.05% (ointment, cream, lotion)

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
  • 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
  • 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
  • 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
  • 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
  • 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 reinfection.
  • 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
  • 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 mupriocin 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
  • Present as clusters of 2-3 mm umbilicated clear or hemorrhagic vesicles persisting for 5-10 days usually preceded by locaozlied 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: 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 moisturefree 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 Pityriasis Rosacea
  • 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)
  • 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
  • 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 prescriptionstrength 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
  • Open and closed comedones, noninflammatory versus inflamed papules/pustules
  • 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
  • Type of eczema caused by allergic reaction to allergen (type IV hypersensitivity), usually 48-72 horus after exposure
  • Symptoms include erythematous, indurated pruritic plaques, +/- edema, +/- blistering, +/- scale
  • Consider triggers such as nickel, fragrances/perfumes, work exposures, poison ivy
  • Determine allergin, 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
  • Actue/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
  • 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
  • Chronic inflammatory condition affecting central face, usually appears between 30-60 yo
  • Persistent facial redness, teangiectasia, 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

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