Hair & Nail Disorders; Lice, Scabies, & Spider Bites Flashcards
Onychomycosis
Tinea Unguium
Nail fungal infection - usually Trichophyton rubrum
Typically toes, distal subungual
Brittle, lusterless, hypertrophic discolored nails
Distinguish from nail dystrophy w/ KOH prep, culture, or biopsy
Treat if: Hx LE cellulitis, DM pt, discomfort/pain, cosmetic
Onychomycosis Treatment
Oral Terbinafine (Lamisil) is treatment of choice w/ fewer SE
-Topical treatment doesn’t penetrate
High reoccurance rate regardless of treatment method
Fingernails - 1.5-3 months; Toenails - 3-12 months
Monitor LFTs to watch for hepatotoxicity or liver failure
Lamisil is CI w/ statins
Always screen for Diabetes
Paronychia
-Infection around fingernail - usually Staph aureus
Tx: Antibiotics, warm soaks if mild; I&D if severe
Felon
- Closed compartment pulp space infection on digit tip with no pus
- Swollen, tender, erythematous - can cause necrosis and compromise vascular supply
Tx: I&D, Abx, refer to hand surgeon
Herpetic Whitlow
Tense vesicle cluster on erythematous base
Common in kids and healthcare workers
Tx: self-limited, topical acyclovir is not effective- do oral, especially w/ immunocompromised
Onychocryptosis
Ingrown nail
Lateral nail plate pierces lateral nail fold - enters dermis
-Pain, edema, exudate, granulation of tissue
Caused by poorly fitting shoes, excessive trimming, trauma
Tx: mild/moderate: cotton ball, warm soaks
- Moderate/severe: removal, Abx - Cephalexin
- Don’t use lido + epi on toes
Androgenic Alopecia
Symmetrical hair loss beginning @ frontoparietal scalp
Dihydrotestosterone (DHT) inhibits scalp hair growth and stimulates facial hair growth
Genetic, hormonal, relates to age and gender
Tx: Finasteride (Propecia) - blocks DHT, lowers PSA
-Topical Minoxidil (Rogaine) for younger w/ balding <10 years
Alopecia Areata
Autoimmune process against hair follicle - associated w/ pernicious anemia and Hashimoto’s
Rapid, distinct hair loss - not thinning, w/ complete patches gone
Alopecia Totalis (entire scalp), or Alopecia Universalis (all body hair gone)
Tx: Intralesional steroids/potent topical steroids for isolated patches
- Topical immunotherapy w/ >50% hair loss
- 2nd line: Minoxidil, Anthralin
Normal Hair Cycle Stages
Anagen = active growth - lasts for 2-6 years
Catagen = transition w/ root dissolving - 1-2 wks
Telogen = resting phase, no root - 5-6 wks
Return to Anagen w/ new hair bulb formed and old hair lost
Telogen Effluvium
Alopecia - alteration of normal hair cycle
-Thinning/shedding causes by early entry into telogen phase
Latency for 3-4 months
Risk: stress, post-partum, malnutrition, diet, metabolic
Tx: identify trigger
Trichotillomania
Alopecia - Impulse control disorder resulting in irregular, short hairs
Usually unilateral to patients dominant hand
Tx: SSRI, cognitive therapy
Pediculosis
Lice: Capitus = head; Corporis = body
Pubic lice = screen for other STIs
-Pruritis, may take 2-6 weeks to manifest; can get secondary cellulitis from scratching
Tx: 2 mechanisms - Neurotoxicity w/ Permethrin (Nix) 1st line, suffocation w/ Benzyl ETOH (Ulesfia) lotion
-Spinosad (Natroban) for hyperexcitation & death by paralysis
Scabies
Sarcoptes Scabiei Mite
Burrows under skin and causes intense itching that is worse @ night
Mites @ hands/wrists, rash @ axilla, genitals, knees, abdomen
Tx: Permethrin Cream is TOC - apply head to toes for 8-14 hours then wash, repeat 7 days PRN
-Safe >1mo, pregnancy - SE: burning, stinging, itching, rash
Lindane lotion is more neurotoxic, Oral Ivermectin is more effective than lindane but CI w/ pregnancy/lactating
Three most common pediatric skin diseases
Scabies
Tinea
Pyoderma
Black Widow
Worldwide spiders, usually outside/abandoned structures
-Leave unremarkable local lesions w/ characteristic systemic rxn and alpha-latrotoxin
May take 8 hrs, usually bite on LE - initial asx/mild pain that progresses to systemic muscle pain in extremities, abdomen, back
-Also tremor, weakness; nonspecific in kids - distressed, inconsolable, refuse food/drink, generalized erythema
