Pharmacotherapy - Dermatology I Infections, Infestations, Bumps

Vocabulary flashcards covering key terms and concepts from lecture notes on fungal infections (tinea), warts, insect bites/stings, pediculosis (lice), and scabies, including treatments, nonpharmacologic approaches, and exclusions for self-care.

Tinea capitis

Fungal infection of the scalp; cannot be treated with self-care; four presentation types: noninflammatory, inflammatory, black dot, favus.

Tinea pedis

Athlete’s foot; the most common fungal skin infection; four variants: chronic intertriginous, chronic papulosquamous, vesicular, ulcerative.

Tinea cruris

Fungal infection of the groin (jock itch); highly itchy; located on medial and upper thighs and pubic area.

Tinea corporis

Fungal infection of the body (ringworm); common in warm, humid climates; circular red, scaly patches.

Tinea unguium (onychomycosis)

Nail fungal infection; nails become thick, yellow, and friable; cannot be self-treated; requires prescription or surgical management.

Trichophyton

Dermatophyte fungus commonly causing superficial fungal infections of skin (one of the main causes of tinea).

Microsporum

Dermatophyte fungus causing dermatophyte infections; can be animal-associated.

Epidermophyton

Dermatophyte fungus contributing to superficial fungal infections of skin and nails.

Candida (yeast)

Yeast that can cause fungal infections; less commonly the cause of superficial dermatophyte infections; OTC products may not be indicated for Candida.

Self-care exclusions (nails or scalp involved)

Nails or scalp involvement excludes self-care and may require prescription therapy or procedures.

Uncertainty or persistent infection exclusion

If causative factor is unclear or infection persists/worsens despite treatment, refer or pursue prescription therapy.

Location-based presentation of fungal infections

Fungal infections commonly occur where moisture is present: feet, groin, scalp, armpits.

General signs of fungal infection

Mushy or malodorous skin, rash, scaling, inflammation, cracks; itching and pain may occur.

Fungus treatment goals

Relieve symptoms, eradicate infection, and prevent future infections.

OTC antifungals: Terbinafine

Terbinafine 1% (brand example: Lamisil) topical antifungal; fast-acting for tinea pedis, cruris, corporis.

OTC antifungals: Miconazole

Miconazole 2% (brand examples: Micatin, Lotrimin AF Powder); used for tinea pedis, cruris, corporis.

OTC antifungals: Clotrimazole

Clotrimazole 1% (brand: Lotrimin AF Cream); used for tinea pedis, cruris, corporis.

OTC antifungals: Butenafine

Butenafine 1% (brand: Lotrimin Ultra Cream); used for tinea pedis, cruris, corporis; fast-acting option.

OTC antifungals: Tolnaftate

Tolnaftate 1% (brand: Tinactin Cream or Powder Spray); used for tinea pedis, cruris, corporis; slower-acting option.

OTC antifungals: Brand vs. generic naming

Common OTC products combine brand names (e.g., Lotrimin AF, Tinactin) with their active ingredients (miconazole, tolnaftate, etc.).

Nonpharmacologic management of fungal infections

Hygiene and prevention: use separate towels, don’t share clothing, wash contaminated items in hot water, keep skin dry, wear breathable fabrics, and dispose of damp footwear appropriately.

Key body-area species treatment limits

Tinea capitis and tinea unguium typically cannot be managed solely with self-care; require prescription therapies or procedures.

Warts etiology

Caused by human papillomavirus (HPV); common skin lesions that may clear spontaneously.

Salicylic acid MOA

Keratolytic agent that helps thin and remove infected skin; available from 5% to 40% concentrations; typically used for 6–12 weeks.

Salicylic acid treatment duration for warts

Visible improvement usually within 1–2 weeks; complete clearance may take 6–12 weeks depending on product strength.

Duct tape wart treatment

Nonpharmacologic method: apply duct tape to plantar lesions; continue cycle of application and soaking/file as outlined.

Cryotherapy ingredients (OTC)

Cryotherapy products use dimethyl ether and propane (DMEP) or nitrous oxide (NO) to freeze warts.

DMEP cryotherapy directions

Place canister on wart, apply for about 20–40 seconds, wart often falls off around 10 days later; repeat if needed.

OTC wart products (brands)

Brand examples include Compound W, Dr. Scholl’s; products vary by salicylic acid strength and formulation (pads, gels, strips, etc.).

Common wart anatomy vs plantar wart

Common warts: skin-colored, rough; plantar warts: on bottom of foot, hyperkeratotic and may resemble calluses.

Insect repellent DEET

N,N-diethyl-m-toluamide; effective all-purpose repellent; use 30% or less in children; apply after sunscreen, not to cuts, and reapply every 4–8 hours.

Safety guidelines for DEET use

Do not apply to hands/eyes/mouth; avoid use in infants under 2 months; apply sunscreen first, and wash treated skin after outdoor exposure.

Alternatives to DEET: Picaridin

Picaridin-based repellents (e.g., Cutter Advanced) offer comparable protection with potentially less odor and irritation.

Permethrin use for lice

Topical cream rinse for head lice; apply to damp hair, rinse after 10 minutes; reapply 9 days later if live lice are observed.

Synergized pyrethrins (RID) MOA

Pyrethrin combined with piperonyl butoxide to prevent breakdown; paralyzes lice by blocking nerve impulses.

Synergized pyrethrins dosage rules

Apply enough to wet the hair (dry hair); leave for about 10 minutes; rinse; comb with a lice comb; repeat in 9 days; do not exceed twice in 24 hours.

Ivermectin topical (Sklice)

0.5% lotion; single application to dry hair; kills live lice and eggs; no combing required.

Spinosad (Natroba)

0.9% suspension; kills lice and eggs via neuronal disruption; FDA approved for 6 months and older.

Malathion (Ovide)

0.5% lotion; applied to dry hair and left to dry; wash off after 8–12 hours; repeat in 7–9 days if needed; flammable; prescription option.

Lice resistance and management

Resistance to permethrin and pyrethrins observed; alternative prescription options (ivermectin, spinosad) may be used.

Lice exclusion criteria for self-care

Age restrictions (pyrethrins before 2 years; permethrin before 2 months); eyelid/eyebrow infestation; pregnancy considerations.

Pediculosis nonpharmacologic care

Wet-combing with a lice comb; wash and dry items in hot water or seal in bags for 2 weeks; vacuum household items; avoid sharing combs/hats.

Scabies etiologic agent

Infestation with the mite Sarcoptes scabiei.

First-line scabies treatments

Topical permethrin 5% cream (Elimite) or oral ivermectin (Stromectol); alternative options include spinosad, crotamiton; lindane is controversial.

Crusted (Norwegian) scabies

Severe form in elderly, immunocompromised, or crowded settings; requires aggressive combination therapy (ivermectin plus 5% permethrin).

Scabies transmission prevention

Treat all close contacts simultaneously; decontaminate items; isolate affected individuals until 24 hours after treatment begins.

Scabies itching management

Antihistamines (oral or topical), low-toxicity corticosteroids, and moisturizers to relieve itching after infestation treatment.

Prevention and decontamination for infestations

Wash clothes and bedding; isolate treated individuals; decontaminate environments to prevent reinfestation.

Key points for self-care eligibility

Know which infections or locations can be managed at home and which require professional referral (e.g., nail/scalp involvement, extensive disease, or suspected secondary infection).