Dermatology (4%)

Acneiform Eruptions

• Acne vulgaris

  • comedones (open/closed), inflammatory papules/pustules
  • puberty, PCOS, steroids/lithium
  • Tx: 1st line - topical retinoids +/- abx, OCP / spironolactone (females) / 2nd line: doxycycline / 3rd line OR severe: accutane

• Folliculitis

  • hair follicles, S. aureus (sometimes viral/fungal)
  • Tx: topical mupirocin/clindamycin

• Perioral dermatitis

• Rosacea

  • no comedones, w/ flushing/telangiectasias
  • Tx: lifestyle, afrin, metronidazole, oral abx

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Desquamation

• Erythema multiforme
  • NEGATIVE Nikolsky sign
  • Type IV hypersensivity reaction (bactrim, beta lactams, infections)
  • Tx: stop offending agent, symptomatic management
• Stevens-Johnson syndrome / Toxic epidermal necrolysis
  • SJS: <10% BSA, TEN: >30% BSA (10-30% = SJS/TEN OVerlap)
  • POSITIVE Nikolsky sign
  • Widespread flacccid bullae
  • MC: meds (sulfa, lamotrigine)
  • Tx: stop offending agent, burn unit, fluid/electrolyte replacement

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Diseases/Disorders of the Hair and Nails

• Alopecia

• Onychomycosis

• Paronychia / felon

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Envenomations and Arthropod Bite Reactions

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Infectious Diseases

Bacterial

• Cellulitis
  • begins at site of a minor trauma,
  • Tx: oral abx
• Erysipelas
  • Tx:
• Impetigo
  • honey crusted, young children
  • Tx: topical mupirocin

Fungal

• Candidiasis
  • classified by locations: thrush (mouth), intertrigo (beefy red body folds), vaginaal candidiasis
  • Tx: nystatin, keep area cool + dry
• Dermatophyte infections
  • Classified by location: Tinea +
  • Tx: topical antifungals
  • Special cases:
    • Tinea capitus: oral antifungals (griseofulvin, terbinafine)
      • Kerion

Parasitic

• Lice
  • uncontrollable itching
  • Tx: permethrin (cream for body, shampoo for hair)
• Scabies
  • intense itching at NIGHT
  • linear burrows in web spaces, intertriginous areas
  • red itchy papules in groin/body folds/between fingers/toes
  • Tx: permethrin cream (treat close contacts too)

Viral

• Condyloma acuminatum
  • genital warts
  • HPV 6, 11
  • Tx: cryotherapy, imiquimod, cantharidin
  • Prevention: Gardasil
• Exanthems
  • Viral Exanthems
• Hand-foot-and-mouth disease
  • Coxsackie A
  • Tx: supportive
• Herpes simplex
  • HSV 1/2
  • Grouped vesicles
  • Dx: PCR or Tzanck smear
  • Tx: oral antivirals (valacyclovir, acyclovir)
• Molluscum contagiosum
  • poxvirus
  • flesh colored papules with central umbilication
  • Tx: supportive care (unless genital, then cryotherapy)
• Varicella-zoster virus infections
  • Chicken pox
    • “dew drops on rose petal”, multiple stages
    • Tx: supportive care
  • Shingles
    • dermatomal, hutchinson sign (CNV1, ophthalmic zoster), Ramsey-hunt syndrome (CNVII involvement, oticus zoster)
    • postherpetic neuralgia
    • Tx: valacyclovir, acyclovir
    • Prevention: shingrix vaccine
• Verrucae
  • warts - plantar, etc (HPV)
  • Tx: salicylic acid, cryotherapy, imiquimod, cantharidin

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Keratotic Disorders

• Actinic keratosis

• Seborrheic keratosis

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Neoplasms

• Benign
  • Seborrheic Keratosis
    • benign hyperkeratotic papule, increasing prevalence with age
  • Solar Lentigines
    • “liver spots”, flat macules on sun exposed areas
• Malignant
  • Basal Cell Carcinoma
    • MC cancer in humans
    • locally destructive, rearely metastatic
    • “pearly papule”, non-healing lesion in sun-exposed area
    • Tx: surgical excision
  • Squamous Cell Carcinoma
    • MC cancer in immunosuppressed individuals
    • Other Rf: >50, fair skin, sun exposure
    • Tx: surgical excision
  • Melanoma
    • breslow depth
    • ABCDE moles
    • Tx: wide surgical excision +/- sentinel node biopsy
• Premalignant
  • actinic keratosis
    • sun exposed skin (forehead, face)
    • risk of progression to SCC
    • Tx: cryotherapy, topical 5-FU

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Papulosquamous Disorders

• Atopic dermatitis

  • flexural, chronic (usually childhood onset), ITCHY
  • Nummular eczema: coin shaped lesions
  • Dyshidrotic eczema: itchy vesicles on hands/feet
  • Tx: topical steroids

• Contact dermatitis

  • irritant / allergic (poison ivy, nickel, detergents)
  • ITCHY
  • Dx: patch testing
  • Tx: topical steroids, avoid irritants

• Drug eruptions

  • delayed type IV
  • 4-21 days after starting drug
  • Usually not itchy, maculopapular rash on trunk
  • Tx: stop offending agent

• Eczema

• Lichen planus

  • ITCHY rash on extremities
  • purple, polygonal, planar, pruritic, papulas/plaques
  • Tx: topical steroids

• Pityriasis rosea

  • Herald patch, “salmon colored” macules, “christmas tree” pattern
  • Tx: selm limiting

• Psoriasis

  • MC: plaque psoriasis, extensors surfaces
  • Nails, skin, joints (psoriatic arthritis)
  • Tx: topical steroids, calcineurin, biologics (humira/skyrizi), immunosuppressives (severe)

• Seborrheic dermatitis

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Pigment Disorders

• Melasma

• Vitiligo

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Skin Integrity

• Burns

• Lacerations

• Pressure injury

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Vascular Abnormalities

• Cherry angioma

  • benign, no treatment

• Hemangioma

  • neonatal (propanolol)

• Purpura

• Stasis dermatitis

  • 2/2 chronic venous insufficiency
  • Lipodermatosclerosis
  • Pruritis, scaling, lichenification, hyperpigmentation
  • Tx: steroids

• Telangiectasia

  • “spider veins”, benign superficial cutaneous veins
  • Tx: vascular laser

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Vesiculobullous Disease

• Bullous Pemphigoid
  • TENSE blisters
• Pemphigus Vulgaris
  • FLACCID blisters
  • multiple flaccid blisters (positive Nikolsky), usually have mucocutaneous component
  • Dx: skin biopsy
  • Tx: high dose oral steroids, wound care, immunosuppressants

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Other Dermatologic Disorders

• Acanthosis nigricans

• Hidradenitis suppurativa

  • acne inversa
  • Rf: genetic, obesity, female, smoking
  • Tx: topical clindamycin, intralesional triamcinolone, abx, de-roofing, I&D

• Lipomas / epidermal inclusion cysts

• Photosensitivity reactions

• Pilonidal disease

• Urticaria

  • Type 1 (IgE) hypersensitivity reaction
  • “hives”
  • Tx: antihistamines

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