PANCE Blueprint Dermatology (5%)

Lessons

1. Dermatology Comprehensive Exam (Members Only)
2. Dermatology Flashcards (Members Only)

3. Eczematous Eruptions (PEARLS)
   1. Dermatitis (ReelDx)

      • Contact dermatitis: Well-demarcated erythema, erosions, vesicles
      • Atopic dermatitis: Pruritic papules and plaques
      • Nummular eczema: Coin-shaped/discoid plaques
      • Seborrheic dermatitis: Erythematous/yellow, scaly crusted lesions. Kids (scalp), adults/adolescents (body folds)
      • Perioral dermatitis: Young women. Papulopustules, plaques and scales around mouth
   2. Dyshidrosis (ReelDx)

      Tapioca vesicles on the lateral aspects of fingers, the central palm, and plantar surfaces following stress or hot humid weather
   3. Lichen simplex chronicus

      Lichen simplex chronicus (LSC) is a chronic dermatitis resulting from chronic, repeated rubbing or scratching of the skin. Skin becomes thickened with accentuated lines (“lichenification”). The constant scratching causes thick, leathery, brownish skin.
4. Papulosquamous Diseases (PEARLS)
   1. Drug eruptions (ReelDx)

      An adverse cutaneous reaction in response to administration of a drug. Skin reactions are the most common adverse drug reactions. Severity can range from mild eruptions that resolve after the removal of the inciting agent to severe skin damage with multiorgan involvement.
   2. Lichen planus

      Lichen planus (LP) is a chronic papulosquamous inflammatory dermatosis of unknown etiology, probably autoimmune in origin

      • Clinically characterized by 5Ps purple, papule, polygonal, pruritis, planar
      • Wickham striae: whitish lines visible in the papules of lichen planus and other dermatoses
   3. Pityriasis rosea (ReelDx)

      Pityriasis rosea typically occurs in children and young adults. It is characterized by an initial herald patch, followed by the development of a diffuse papulosquamous rash. Pityriasis rosea is easier to identify when the general eruption appears with smaller secondary lesions that follow Langer’s lines (cleavage lines) in a Christmas tree-like pattern.
   4. Psoriasis (ReelDx)

      The classic clinical appearance is a well-demarcated, erythematous plaque with silver scaling. Patients may also present with no rash and only joint symptoms - pain in both hands and nail changes such as pitting and onycholysis.

      • Auspitz sign (bleeds when scale is picked), Koebner’s phenomenon (minor trauma causes new lesion)
        • Psoriasis Vulgaris: most common. Noted on extensor surfaces
        • Guttate Psoriasis: children, after URI. small lesions
        • Inverse Psoriasis: intertriginous areas.
        • Pustular Psoriasis: contains pustules
5. Desquamation (PEARLS)

   1. Erythema multiforme (ReelDx)

      Erythema multiforme (EM) is an acute, self-limited skin condition that is considered to be a type IV hypersensitivity reaction associated with certain infections - most commonly herpes simplex virus (HSV), medications (sulfa drugs), and other various triggers.

      • Skin lesions predominantly involving the extremities (hands, feet, and mucosa). Target-like shape, raised, blanching, and lack of itchiness help characterize this rash.
   2. Stevens-Johnson syndrome

      SJS is 3-10% of the body - rare, serious hypersensitivity complex that affects the skin and mucous membranes. It's usually a reaction to a medication or an infection commonly caused by anticonvulsants and sulfa drugs.

      • Begins with a prodrome of flu-like symptoms, followed by a painful red or purplish rash that spreads and blisters. Layers of skin peel away in sheets (+) Nikolsky's sign (pushing blister causes further separation from dermis)
   3. Toxic epidermal necrolysis

      TEN is > 30% of the body surface area - is a more severe form of Stevens-Johnson syndrome. More common in adults.
6. Vesicular Bullae (PEARLS)
   1. Bullous pemphigoid

      Bullous pemphigoid is a rare, chronic acquired autoimmune subepidermal blistering skin disorder caused by linear deposition of autoantibodies against the epithelial basal membrane zone: IgG produced against the basement membrane.

      • Large bullae and crusts located on axillae, thighs, groin, abdomen. More tense, less fragile and deeper than pemphigus vulgaris.
7. Acneiform Lesions (PEARLS)
   1. Acne vulgaris (ReelDx)

      Characterized by areas of open comedones (blackheads) incomplete blockage, closed comedones (whiteheads) complete blockage, papules, pustules, nodules or cysts. may result in scarring.

      • I - Comedonal: comedones (+/- small amounts of papules and pustules)
      • II - Papular: moderate number of lesions, little scarring
      • III - Pustular: lesions > 25, moderate scarring
      • IV - Nodulocystic: severe scarring
   2. Rosacea

      Rosacea - women aged 30-50, facial erythema, telangiectasias, papules, may cause rhinophyma. Triggers include heat, alcohol, spicy foods, treat with topical metronidazole

      • Differentiate from acne by lack of comedones (blackheads)
8. Verrucous Lesions (PEARLS)
   1. Actinic keratosis

      Actinic Keratosis - flesh-colored, pink or yellow-brown lesion with rough sandpaper feel, occurs on sun-exposed surfaces and is a precursor to squamous cell carcinoma
   2. Seborrheic keratosis

      Seborrheic keratosis - most common benign skin tumor seen in fair-skinned elderly patients with prolonged sun exposure, brown-black plaques with waxy, “stuck on” appearance, commonly referred to as barnacles of old age

9. Insects/Parasites (PEARLS)
   1. Lice (ReelDx)

      Pruritic scalp, body or groin. Nits are observed as small white specs on hair shaft. Body (corporis); Pubic (pubis), launder potential fomites such as sheets in hot water (> 131 F or 55 C)
   2. Scabies (ReelDx)

      Pruritic papules. S-shaped or linear burrows on the skin. Often located in web spaces of hands, wrists, waist with severe itching (worse at night), treated with topical permethrin, all clothing bedding, towels washed and dried using heat and have no contact with body for at least 72 hours
   3. Spider bites (ReelDx)

      • Brown Recluse spider bites (necrotic wound) tend to cause pain, erythema, ecchymosis, and bleb formation, sometimes with surrounding ulceration and necrosis
      • Black Widow spider bites (neurologic manifestations) generalized muscle pain, spasms, and rigidity. May not see much at the bite site.
10. Dermatologic Neoplasms (PEARLS)
    1. Basal cell carcinoma

       Basal Cell Carcinoma - raised pearly borders, telangiectasis, central ulcer (Rodent ulcer)
    2. Kaposi sarcoma

       KS is a violaceouspapular lesion associated with human herpesvirus 8 and is an AIDS-defining cancer
    3. Melanoma

       ABCDE: Asymmetry, Border is irregular, Color variability (blue, red, white), Diameter (increasing or > 6 mm),  elevation (raised). Prognosis of a melanoma is most strongly associated with the depth of the lesion, uses Clark Classification System of Microstaging
    4. Squamous cell carcinoma

       Cutaneous SCC present as enlarging hyperkeratotic macule, scaly or crusted lumps. They often arise within pre-existing actinic keratosis
11. Hair and Nails (PEARLS)
    1. Alopecia (ReelDx)

       • Tinea capitis: Hair loss secondary to fungal infection of the scalp
       • Alopecia areata: Oval shaped well-demarcated hair loss, autoimmune attack against hair follicles
       • Traction alopecia: Caused primarily by pulling force being applied to the hair (tight hairstyles)
       • Telogen effluvium: Diffuse hair loss that occurs after stress, illness, medication
       • Androgenic alopecia:  Typical male pattern baldness
    2. Onychomycosis

       Onychomycosis: Thick, yellow, brittle nails. Treat 6 weeks for fingernails and 12 weeks for toenails. LFT monitoring is necessary for most oral antifungal regimens.
    3. Paronychia (ReelDx)

       Paronychia: Superficial inflammation of the lateral and posterior folds of skin surrounding the fingernail or toenail. Caused by candida if chronic and staph aureus if acute

12. Viral Dermatologic Diseases (PEARLS)
    1. Condyloma acuminatum (genital warts)

       Genital warts - flesh-colored, cauliflower appearance  caused by HPV types 6 and 11

       • The HPV quadrivalent vaccine (Gardasil) protects against 6 and 11 and the 2 most cancer-promoting types, 16 and 18 indicated for females and males ages 9–26 years
    2. Viral Exanthems

       • Rubeola (measles): 4 C's: cough, coryza, conjunctivitis and cephalocaudal spread of morbilliform (maculopapular, brick red rash on face beginning at hairline then progressing to palms and soles last - rash lasts 7 days). Koplik spots (small red spots in buccal mucosa with blue-white pale center) precedes rash by 24-48 hours.
       • Rubella (German measles): 3-day rash -  pink light-red spotted maculopapular rash with cephalocaudal spread - appears on the face, spreads caudally to the trunk and extremities and becomes generalized within 24 hours (lasts 3 days). Lymphadenopathy (posterior cervical, posterior auricular) Teratogenic in 1'st trimester. 
       • Roseola (sixth disease): Herpesvirus 6 or 7, only childhood exanthem that starts on the trunk and spreads to the face. High fever 3-5 days then rose pink maculopapular blanchable rash on trunk/back and face.
       • Erythema infectiosum (fifth disease): Parvovirus B19 - "slapped cheek" rash on face - lacy reticular rash on extremities, spares palms and soles resolves in 2-3 weeks.
       • Coxsackievirus (hand, foot, and mouth disease): children< 10 years old with vesicles on pharynx, mouth, hands, feet.
    3. Herpes simplex (ReelDx)

       There are eight types of herpes viruses known to affect humans. They are called the Herpes Human Viruses (HHV). There are two types of Herpes Simplex viruses: HSV 1- Oral lesions, HSV 2 - Genital lesions

       • HSV 1 - Oral lesions (tongue, lips etc.)
       • HSV 2 - Genital lesions (vulva, vagina, cervix, glans, prepuce, and penile shaft)
       • HHV 3 - VZV (Varicella Zoster Virus commonly known as chickenpox or shingles)
       • HHV 4 - EBV (Ebstein Barr Virus is commonly known as infectious mononucleosis [mono or glandular fever])
       • HHV 5 - CMV (Cytomegolo Virus is the most common virus transmitted to a pregnant woman's unborn child)
       • HHV 6 - Roseolovirus is more commonly known as the 6th disease or Roseola Infantum
       • HHV 7 - Similar to HHV6 (not yet classified)
       • HHV 8 - A type of rhadinovirus known as the Kaposi's sarcoma-associated herpesvirus (KSHV)
    4. Molluscum contagiosum (ReelDx)

       Molluscum contagiosum: caused by the poxvirus, pearly papules with central umbilication
    5. Varicella-zoster virus infections (ReelDx)

       • Chickenpox: Vesicular lesions in different stages of development. Dewdrop on rose petal
       • Shingles: Pain precedes rash groups of vesicles in a unilateral dermatomal pattern - Tzanck prep is positive for multinucleated giant cells. Hutchinson’s sign - lesion on the nose. Concern for eye involvement
    6. Verrucae

       Warts: all warts are caused by the Human Papillomavirus (HPV)

       • Verruca vulgaris (common warts): skin colored papillomatous papules. Hands
       • Verruca plana (flat warts): face, arms, legs
       • Verrucae plantaris (plantar warts): bottom of the foot. Rough surface. Dark spot (thrombosed capillaries)
       • Condyloma acuminatum (venereal warts): flesh-colored, cauliflower appearance genital warts caused by HPV types 6 and 11

13. Bacterial Infections (PEARLS)
    1. Cellulitis (ReelDx)

       Cellulitis: An acute bacterial skin and skin structure infection of the dermis and subcutaneous tissue; characterized by pain, erythema, warmth, and swelling, margins are flat and not well demarcated. Caused by Staphylococcus and Streptococcus in adults. H. influenzae or strep pneumonia in children
    2. Erysipelas

       Erysipelas: a distinct form of cellulitis notable for acute, well-demarcated, raised superficial bacterial skin infection with lymphatic involvement almost always caused by Streptococcus pyogenes. Fever and chills.
    3. Impetigo (ReelDx)

       Impetigo: nonbullous, golden honey colored crusts around nose and mouth, concurrent bullous, thin-walled vesicles. Staphylococcus aureus is most common
14. Fungal Infections (PEARLS)
    1. Candidiasis (ReelDx)

       Beefy red sharp bordered rash with pinpoint satellite pustules at the edge of erythema. Potassium hydroxide wet mount of skin scrapings - budding yeast, hyphae, and pseudohyphae. Favors skinfolds/creases (axillae, groin, below breasts, and, in infants, diaper area)

       • Vulvovaginal candidiasis: A yeast infection of the vagina and tissues at the opening of the vagina (vulva)
       • Candidiasis of skin and nails: An infection of the skin and nails caused by the candida fungus
       • Oral thrush: An infection in which the fungus Candida albicans accumulates in the mouth
    2. Dermatophyte Infections (ReelDx)

       KOH - long, branching fungal hyphae with septations

       • Tinea Barbae: papules pustules, around hair follicles
       • Tinea Pedis: Athlete's Foot: pruritic scaly eruptions between toes. Trichophyton rubrum is the most common dermatophyte causing athlete’s foot  Mgmt: Topical antifungals
       • Tinea Cruris: “Jock Itch” diffusely red rash in the groin or on the scrotum.
       • Tinea capitis: Most common fungal infection in the pediatric population. Occurs mainly in prepubescent children (between ages 3 and 7 years). Asymptomatic carriers are common and contribute to spread
       • Tinea corporis: (ringworm): usually seen in younger children or in young adolescents with close physical contact with others (i.e. wrestlers)
       • Tinea versicolor: is caused by Malassezia furfur, a yeast found on the skin of humans. Lesions consist of hypo or hyperpigmented macules that do not tan

15. Other Dermatological Conditions (PEARLS)
    1. Acanthosis nigricans (ReelDx)

       Acanthosis nigricans: Thick velvety hyperpigmentation and accentuated skin lines at skin folds - around the neck, armpits, and groin. Associated with insulin resistance -control blood sugars, weight loss, smoking cessation, Metformin.
    2. Burns (ReelDx)

       Body percentage:

       • Rule of 9’s: Head 9%, Each arm 9%, Chest 9%, Abdomen 9%, Each anterior leg 9%, Each posterior leg 9%, Upper back 9%, Lower back 9%, Genitals 1%
       • Palmar method: Patient’s palm equates to 1%

       Degree involvement:

       • 1st degree (sunburn): Erythema of involved tissue, skin blanches with pressure, skin may be tender
       • 2nd degree (partial thickness): Skin is red and blistered, skin is very tender
       • 3rd degree (full thickness): Burned skin is tough and leathery, skin non-tender
       • 4th degree: Into the bone and muscle
    3. Hidradenitis suppurativa

       Hidradenitis suppurativa: Chronic follicular occlusive disease manifested as recurrent, tender, inflammatory nodules, abscesses, sinus tracts, and complex scar formation in the axilla and groin
    4. Lipomas/epithelial inclusion cysts

       Lipoma: Benign, generally slow growing, adipose tumors - if the presenting lesion is fast growing, suspect another diagnosis
    5. Melasma

       Melasma: Hyperpigmented macules in sun-exposed areas, also known as chloasma, or the mask of pregnancy when present in pregnant women.
    6. Pilonidal disease

       Pilonidal disease: A teenager with pain, discomfort and swelling above the anus or near the tailbone (sacrococcygeal cleft) that comes and goes.
    7. Pressure ulcers

       Sacrum and hip most often affected, reposition every 2 hours

       • Stage 1: erythema of localized area, usually non-blanching over bony surface
       • Stage 2: partial loss of dermal layer, resulting in pink ulceration
       • Stage 3: full dermal loss often exposing subcutaneous tissue and fat
       • Stage 4: full thickness ulceration exposing bone, tendon, or muscle. Osteomyelitis may be present
    8. Urticaria (ReelDx)

       Urticaria (hives): Pt will present with blanchable, edematous pink papules, wheals or plaques.

       • (+) Darier's sign: localized urticaria appearing where the skin is rubbed (histamine release)
       • Angioedema: painless, deeper form of urticaria affecting the lips, tongue, eyelids hand and genital
       • If anaphylaxis: Epinephrine: 0.3–0.5 mg; use 1:1,000 dilution for IM route and 1:10,000 for IV route (peds: epinephrine 0.01 mg/kg SC/IV)
    9. Vitiligo (ReelDx)

       Vitiligo: Autoimmune destruction of melanocytes, a Wood’s light examination reveals a “milk-white” fluorescence over the lesion, treat with sunscreen, cover up, corticosteroids, tacrolimus, vitamin D.