Derm 2

Question 1

Erythema nodosum

Answer 1

inflammation of the skin and subQ tissue (panniculitis) characterized by tender, red nodules on the shins
usually in pts 20-30 yrs but can occur at any age. F>M (6x).
Usuaully associated with underlying malignancy (“bad sick”)
Etiology: infections, drugs, malignancy, inflammatory/granulomatous dx (sarcoidosis)
S/Sxs: indurated nodules that look like bruises, gradually changing color, with successive crops of nodules. Nodules are very painful. Mostly pretibial. Systemic symptoms such as fever, malaise, joint pain. spontaneous resolution in about 6 weeks.
Dx: By H & P, but must look for underlying disorder. Biopsy, ESR, CRP ANA, CBC, chest x-ray (sarcoid), ASO-titer or pharyngeal culture (for group A beta-hemolytic strep).
DDx: vasculitis, pretibial myxedema, lymphoma

Question 2

Miliaria (heat rash)

Answer 2

Accumulation of sweat beneath eccrine sweat ducts results in obstruction by keratin at the level of the stratum corneum.
S/Sx: Pruritus is common. More in kids/babies. Small red papules with mild itching, occasional pustules.
Diagnosis: H & P
Ddx: baby acne

Question 3

Cellulitis

Answer 3

acute bacterial infection of the skin that goes deep - Look for lines/streaking (lymphangitis = EMERGENCY)
Distribution: Adults- lower leg most common. Children cheeks, periorbital, head, neck Etiology: most common in adults S. aureus, GAS. Children Hib, GAS, S. aureus. Varies with location. Immunocompromise will predispose. IV drug use
S/Sxs: local erythema, heat, edema and tenderness, with lymphangitis and regional lymphadenopathy. Systemic symptoms, if present, include fever, chills, tachycardia, headache, hypotension or delirium (may precede skin sxs).
Diagnosis: H & P. CBC. Culture of exudates or aspirate. Blood cultures if immune compromised. Blood cultures of infected tissue if not responding to therapy.
DDX: DVT, gout, CPPD, septic arthritis, stasis dermatitis, insect bite, erysipelas

Question 4

Cutaneous abscess

Answer 4

localized collection of pus under the skin
S/Sxs: Painful, tender, indurated and erythematous, varying in size from 1-3 cm typically, but mb larger. May be accompanied by local cellulitis, lymphangitis, LAD, fever.
Diagnosis: by H & P, CBC. Gram stain or culture in immunocompromised patients
DDX: hidradenitis supparitiva, ruptured epidermal cysts

Question 5

Erysipelas

Answer 5

superficial cellulitis with dermal lymphatic involvement (streaking)
Distribution: Legs most common, then face
Etiology: GAS, immunocompromise
S/Sxs: Shiny, raised, indurated and plaque-like lesions with distinct margins. Commonly high fever, chills, and malaise, or maybe no systemic symptoms. It has sharp borders, raised, red(deep), hot plaque that spreads rapidly. Regional LAD and tenderness, and may see vesicles, bullae, petechiae. Itching, burning, and pain may be severe. Red, painful streaks along lymph
Complications: scarlet fever, fat necrosis, gangrene. Sudden onset
Diagnosis: By H & P, CBC, blood culture in toxic-appearing patients. Direct culture is often not useful
DDX: Face – herpes zoster, contact derm.

Question 6

Erysipeloid

Answer 6

Like erysipelas except a different bacteria (Erysipelothrix). Violaceous on the hands and forearms and is not hot, though may be tender with fever and malaise. Rare.

Question 7

Erythrasma

Answer 7

Superficial intertriginous infection with Corynebacterium.
S/Sxs: Occurs in toe webs, between fingers, genitals (pink or brown patches) with scaling, fissuring and maceration. May be patchy on the trunk.
Diagnosis: Coral red fluorescence with Wood’s lamp, no hyphae, skin scraping w/KOH
DDX: tinea, candida

Question 8

Folliculitis

Answer 8

Inflammation of the hair follicle. Many different types
Distribution: buttocks, upper legs, face, neck, sternum and upper outer arms most common but can be anywhere except hands and feet
Etiology: S. aureus, fungal, persistent trauma, systemic corticosteroids, pseudomonas (“hot tub” folliculitis
S/Sxs: Pustule or inflammatory nodule that surrounds a hair follicle. Superficial or deep. Mild itching or pain. Abrupt onset May be chronic.
Diagnosis: by examination. KOH to r/o dermatophyt
DDX: acne, follicular keratosis,

Question 9

Furuncle (Boil)

Answer 9

Acute tender nodules, caused by S. aureus
Uncommon in children
Distribution: neck, under breasts, buttocks, groin most commone
S/Sxs: A deep dermal or subq, red, swollen and painful mass and drains to the surface. Pustule 5-30 mm with central necrosis and pus discharge. May be recurrent. A ruptured lesions heals with deep violaceous scar. afebrile
Diagnosis: by examination. Culture may be beneficial dt MRSA
Ddx: Folliculitis, Hidradenitis suppurativa, insect/spider bite, ruptured pilar cyst, cystic acne

Question 10

Carbuncle

Answer 10

Cluster of furuncles with multiple draining orifices.
S/Sxs: Usu on neck, face, breasts and buttocks. Uncomfortable and may be painful, accompanied by fever.
Diagnosis: by examination. Culture if recurrent or immunocompromised.

Question 11

Impetigo

Answer 11

superficial acute skin infection with crusting, common in children
Distribution: face, shins, extensor surface of forearms
Etiology: S. pyogenes, S. aureus. Warm moist climate, poor hygiene
S/Sxs: Clusters of vesicles or pustules that rupture and develop honey colored crust. Scaling borders. Satellite lesions often present. May see regional LA. May be pruritic.
Diagnosis: by examination. Culture is more common now dt MRSA.
DDX: atopic, contact dermatitis, perioral dermatitis, herpes simplex, herpes zoster, tinea

Question 12

Candidiasis

Answer 12

Skin infection with Candida sp, most often Candida albicans (70-80%).
Many different types based on location: Balanitis, Diaper Dermatitis, Intertrigo, Vulvovaginitis, Oropharyngeal
Etiology: Immunosuppression, sugar dysregulation, antibiotics, oral contraceptives
S/Sxs: intertriginous, erythematous, well-demarcated, pruritic patches of varying sizes and shapes. Surface is often glistening. Intense inflammation with satellite lesions around the main area.
Diagnosis: By examination, presence of yeast and pseudohyphae on KOH prep, fungal culture or DNA probe.
DDx: changes with location. Dermatophytoses, allergic derm, herpes, molluscum, psoriasis, contact derm, strep cellulites, seborrheic derm, erythrasma,

Question 13

Dermatophytoses

Answer 13

fungal infections of keratin in the skin and nails.
Etiology: Epidermophyton, Microsporum, and Trichophyton fungi
S/Sxs: Vary by site. Recurrent with little or no inflammation. Mildly pruritic, erythematous scaling lesions.
Diagnosis: by appearance, Wood’s Lamp, skin scraping and a KOH prep.

Question 14

Tinea barbae

Answer 14

uncommon. Develops slowly. 2 patterns- ringworm and follicular. Pruritic, at time painful and swollen. Secondary bacterial infections can occur. Examine skin scraping and plucked hair with KOH (hairs will come out easily if fungal infxn) fungal cultures and biopsy can be helpful.

Question 15

Tinea capitis

Answer 15

caused by Trichophyton tonsurans. More common in African Americans and Hispanic and those living in close proximity. Children most effected. 4 patterns- seborrheic derm, inflammatory, “black dot” pattern and pustular. s/sx change with each. KOH examination of lesional hairs demonstrates fungal hyphae arranged in a longitudinal direction within the hair shafts. Culture can be performed on Sabouraud’s medium and Wood’s lamp examination of infected hairs reveals a characteristic sliver-blue fluorescence DDX: psoriasis, seborrheic dermatitis

Question 16

Tinea corporis

Answer 16

pruritic, circular or oval, erythematous, scaling patch/plaque that spreads centrifugally. Central clearing follows, while the active advancing border, a few millimeters wide, retains its red color and with cross lighting can be seen to be slightly raised. Distribution Dx: KOH will show hyphae, culture may be necessary
DDX: pityriasis rosea, drug eruptions, nummular dermatitis, erythema multiforme, tinea versicolor, psoriasis

Question 17

Tinea cruris (“jock itch”)

Answer 17

Commonly associated with Oobesity, diabetes and immunodeficient states
erythematous patch high on the inner aspect of one or both thighs (opposite the scrotum in men). It spreads centrifugally, with partial central clearing and a slightly elevated, erythematous, sharply demarcated border that may show tiny vesicles that are visible only with a hand glass, spares the scrotum. M>F
Dx: KOH prep from scarping of an active border
DDX: contact dermatitis, psoriasis, Candida, erythrasma, seborrheic derm

Question 18

Tinea pedis (“athlete’s foot”)

Answer 18

common, intensely pruritic, sometimes painful, erythematous vesicles or bullae between the toes or on the soles, frequently extending up the instep. Unilateral or bilateral Secondary eruptions at distant sites, called an Id reaction, examine hands.
Dx: skin scarping.
DDX: dyshidrotic eczema, contact dermatitis, psoriasis

Question 19

Dermatophytid Reaction (“id” reaction)

Answer 19

distant site inflammatory reaction during fungal infection. Sterile.

Question 20

Tinea versicolor

Answer 20

superficial fungus infection with Malassezia furfur (a saprophysic yeast)
S/Sxs: hypopigmented, hyperpigmented, or erythematous macules with scaling patches. Lesions are asx.
Distribution: trunk and proximal upper extremities
Dx: Direct microscopy shows “spaghetti and meatballs” appearance of broad hyphae and clusters of budding cells, Wood’s lamp will reveal yellow to yellow-green fluorescence in some cases
DDX: Vitiligo, pityriasis rosea, tinea corporis, Seborrheic dermatitis, Erythrasma

Question 21

Cutaneous Larva Migrans (“Creeping eruption”)

Answer 21

Etiology: hookworm larva (Ancylostoma) from dog and cat excrement.
S/Sxs: intense pruritis, erythema and papules at site of entry, winding tail of inflammation- serpiginous. usually occurs about 3 weeks after exposure.
Distribution: feet/ankles, buttocks, backs of legs and back
Diagnosis: history and appearance, CBC can show eosinophila, CXR
DDX: scabies

Question 22

Lice (Pediculosis)

Answer 22

Wingless, blood sucking insects that infect the head (Pediculus humanus capitius), body(Pediculosis humanus corporis), or pubis (Phthirus pubis).
S/Sxs: Severe pruritis. May see excoriations from scratching. Red puncta from bites. Nits on hair shaft 1cm from scalp- gray/white. May see brown specks of excrement on skin or clothing.
Distribution: scalp, body hair, pubic hair
Dx: Demonstration of living lice in wet hair using a fine-toothed comb. Also will fluoresce under Wood’s lamp.
DDx: seborrheic derm, impetigo, insect bites

Question 23

Scabies

Answer 23

Infection of skin with scabies mite Sarcoptes.
S/Sxs: Burrows are fine, wavy lines in the skin 2-10 mm long, covered often by lichenified skin. Intensely pruritic, esp at night. May also see erythematous papules without many burrows. Others in family/living quarters will be affected. Itching will continue after treatment due to allergic response not active infestation.
Distribution: hands, arms, feet, gluteal fold, axilla, back of the knees
Diagnosis: Burrows are pathognomonic. May do microscopic examination of burrow scrapings. Apply mineral oil to the burrow, vesicle or papule and scrape with a #15 blade, prepare slide. Dx is often made only by Hx and PE.
DDX: insect bites, fungus, eczema, folliculitis, impetigo

Question 24

Molluscum contagiosum

Answer 24

Etiology: pox virus in epidermal cells, most common 3-9yr
Distribution: face, arms, chest, genitals (when sexually transmitted)
S/Sxs: Smooth flesh colored umbilicated dome, hard; cheesy core; may become inflamed or secondarily infected. Asx. Up to 15 mm in diameter in immunocompromised. Lesions persist for 6-9 months
Diagnosis: By appearance. Biopsy will show “molluscum bodies” in keratinocytes. Biopsy should be used in immunocompromised pts
DDX: Folliculitis, milia, verrucae

Question 25

Warts (Verrucae vulgaris)

Answer 25

Benign contagious neoplasms caused by HPV

Question 26

Common wart (verruca vulgaris)

Answer 26

dome shaped, round or irregular, rough; colors can be gray, yellow, brown, black, skin colored; 2-10 cm. Usually asx. Distribution: hands, knees, genitalia, feet. Age- any but peak at 12-16yrs
Skin lines are interrupted by hyperkeratosis
Black puncta when scraped with pinpoint bleeding

Question 27

Filiform wart

Answer 27

long narrow small warts, soft, seen on eyelids, face, neck

Question 28

Flat wart

Answer 28

Smooth, flat, yellow brown or flesh colored; 2-3 mm; backs of hands, lower legs and face

Question 29

Plantar wart

Answer 29

soles of the feet; single or multiple; painful and callused. Different from corns/calluses – black puncta present.

Question 30

Mosaic wart

Answer 30

multiple plantar warts

Question 31

Condylloma accuminata (genital warts)

Answer 31

soft moist papules or plaques on perineum, external genitalia, anus, vagina, cervix;
Diagnosis: By appearance, biopsy if necessary- esp if it doesn’t respond to tx to r/o squamous cell carcinoma

Question 32

Varicella (chickenpox)

Answer 32

acute highly contagious vesicular eruption caused by a primary infection with varicella (HHV-3). 20% of pt’s vaccinated will still get varicella- although it is atypical dz- maculopapular rash. Infectious from 2 days before the lesions appear till all lesions crust over.
Distribution: begins on trunk and spreads to face and extremities. Most lesions present of trunk Lesions can occur in mouth and vagina
S/Sxs: Prodrome (more in kids > 10) with malaise, chills, headache, sore throat, anorexia and dry mouth. Then the rash starts and itching is severe. Lesions are papules, macules, vesicles, pustules and crusts all at the same time.
Diagnosis: Characteristic rash. Culture or Tzanck smear in questionable cases
DDX: other viral diseases, contact dermatitis, zoster, folliculitis, impetigo

Question 33

Herpes simplex

Answer 33

recurrent viral infection with intraepidermal infection by HSV 1 or 2.
Distribution: mouth, eyes, genitals. Herpetic whitlow infects distal phalanx.
S/Sxs: Single or clustered vesicles. Systemic symptoms with primary infections: fever, malaise, myalgia, headache and regional LA. Prodromal period of tingling or discomfort in many, then appearance of small vesicles on a red base. They
rupture and ulcerate. Often painful. They dry up and are completely healed in about 2-6 weeks. Recurrent infection often follows physical or emotional stress
Diagnosis: characteristic lesions. Tzanck smear (superficial scraping from newly ruptured vesicle, then stained, showing multinucleated giant cells). Definitive dx is with culture of freshly ulcerated lesion.
DDX: impetigo, eczema, zoster, hand foot and mouth dz, aphthous stomatitis

Question 34

Herpes zoster (shingles)

Answer 34

latent varicella (HHV type 3) infection
Distribution: follows dermatome, which can be variable but almost never crosses the midline
S/Sxs: Virus remains in the nerve roots and erupts along the associated dermatome. May start with radicular pain and itching for 2-3 days, followed by herpetic rash. May see systemic symptoms. There may be severe pain, scarring, or post herpetic neuralgia (sharp, intermittent, or constant) which can be debilitating. Lesions usually lasts about 5 days. Pain may last weeks, months, years, or indefinitely.
Diagnosis: pathognomonic rash. Tzanck Smear, differentiate virus by culture.
DDX: changes with stage of dz. Before rash onset: MI, pleurisy, migraine. After lesions appear: HSV, primary varicella

Question 35

Roseola Infantum (Exanthem subitum)

Answer 35

Infection of infants or young children (90% <2yrs) with HHV-6 or 7.
Distribution: Prominent macular rash on chest and abdomen, less so on face and extremities
S/Sxs: 10 day incubation, with 3-5 days of high fever which subsides when the rash appears. May see febrile convulsions. Child is generally alert and active. Cervical and posterior cervical LAD. Rash is present for a few hours to a few days, and possibly unnoticed. Rash may only occur 30% of time.
Diagnosis: Hx and PE, virologic studies in immunocompromised or atypical dz
DDX: Measles, Rubella, Enteroviral infections, Erythema infectiosum, Scarlet fever, drug allergy

Question 36

Hand Foot and Mouth diseas

Answer 36

Febrile disorder caused by Coxsackie virus, most common in children <5yrs
Distribution: buccal mucosa, tongue, palms of hands and feet, occasionally buttocks or genitals.
S/Sxs: vesicular eruption of skin and mucosa (3-6mm), may have fever, myalgia, LA, abd pn, lack of appetite, poor nursing (dt pn). Lesions in mouth are painful. Lesions heal in 7 days
Diagnosis: H & P
DDX: varicella, herpes, herpangina, aphthous stomatitis

Question 37

Viral exanthems

Answer 37

by blood borne viruses initiating a vascular response in the skin. Most present with a prodrome of fever and malaise.

Question 38

Measles (Rubeola, Morbilli)

Answer 38

Extremely communicable viral infection by a paramyxovirus. Spread by secretions from nose, mouth, throat during prodromal and early eruptive phase. Has an incubation time of about 7-14 days, with prodrome around the 9th day.
Distribution: begins on the face and spreading cephalocaudally and centrifugally to involve the neck, upper trunk, lower trunk, and extremities
S/Sxs: prodrome with 3-4 days of fever, coryza, conjunctivitis and photophobia, cough and Koplik spots (these are 1 to 3 mm whitish, grayish, or bluish elevations with an erythematous base on buccal and vaginal surface). Rash appears after 2-3 days of initial symptoms and is morbilliform, maculopapular, and blanching. Lasts 5-6 days.
Complications: encephalitis and secondary infection.
Diagnosis: Clinical – identification of Koplik spots or rash.
Serum anti-measles IgM and IgG; at least fourfold increase in anti-measles antibody titer is indicative of infection.
CBC - Leukopenia, T-cell cytopenia, and thrombocytopenia.
CXR - may demonstrate interstitial pneumonitis)
DDX: during prodrome: many. During rash: Scarlet fever, rubella, drug reactions, roseola, erythema infectiosum, Rocky Mountain spotted fever, infectious mononucleosis, Kawasaki disease, toxic shock syndrome.

Question 39

Rubella (German Measles)

Answer 39

Infection caused by the RNA Rubella virus.
Distribution: first appears on the face, spreads caudally to the trunk and extremities, and becomes generalized within 24 hours
S/Sxs: Usually mild incubation about 14-21 days, with brief prodrome of fever and malaise, with a similar fainter rash, starting on the face and moving downward. Rash is more pinpoint pink maculopapules, and may have petechiae on the soft palate. Very mild dz and may be asx. Does not darken or c oalesce.
Diagnosis: Characteristic LAD and rash. Only need lab dx in pregnant women and newborns- rubella-specific IgM antibodies using an enzyme immunoassay (EIA)
DDX: measles, scarlet fever, drug rashes, erythema infectiosum

Question 40

Vitiligo

Answer 40

Idiopathic condition lacking in melanocytes associated with autoimmune diseases such as thyroid disease, pernicious anemia, systemic lupus erythematosus, and Addison’s disease
S/Sxs: Pigmented areas that are sharply demarcated and often symmetric. Spots are white with no scale. Patchy and irregular, ranging from focal spots, to entire body segments, or most of skin surface.
Diagnosis: obvious on examination. Lesions accentuated under Wood’s Lamp in light skinned pts. thyroid function, CBC, and fasting blood glucose level
DDX: tinea versicolor, Postinflammatory hypopigmentation, Chemically induced depigmentation, Pityriasis alba

Question 41

Melasma/chloasma

Answer 41

macular hyperpigmentation of the face usually seen in pregnant women or using OCP, more in dark skinned races, resulting from an increase in melanin due to estrogen stimulation and UV light. Sharply delineated patches usually on the face. Fades incompletely when the cause is removed.
DDX: post inflammatory hyperpigmentation

Question 42

Lentigines (Lentigo, singular)

Answer 42

flat, tan or brown spots on sun-exposed areas, usu face or back of hands. Due to chronic sun exposure

Question 43

Alopecia (baldness)

Answer 43

Non-scarring alopecia:
- Male pattern baldness: androgenic
- Female pattern: androgenic, starts around menopause.
- Diffuse: dx by pulling 2-3 dozen hairs- if >5 hairs with the bud come out. Triggered by weight loss, stress, pregnancy (or after pregnancy), illness.
- Toxic: related to chemotherapeutic drugs
- Alopecia areata: autoimmune, toxic, genes, infections, drugs, and vaccinations, have been implicated in triggering episodes of alopecia areata. severe stress, especially emotional stress, can precipitate. S/Sx smooth, circular, discrete areas of complete hair loss that develop over a period of a few weeks. Can be whole body.
- Trichotillomania: a psychological disorder related to OCD where pt pulls out hair
- Tinea capitis: see notes above.
Scarring alopecia:
- Cutaneous lupus, deep bacterial infection, ulcers, granulomas, syphilis, tinea
Diagnosis: examine ratio of anagen and telogen hairs to assess if there is normal ratio of resting hairs. Occasional biopsy needed. Look for underlying cause with appropriate labs.

Question 44

Hirsuitism

Answer 44

excess hair in females in areas not normally hairy.
Diagnosis: Serum free/total testosterone, DHEA sulfate, FSH, LH, prolactin, TSH (to check for presence of thyroid dysfunction). Often related to PCOS

Question 45

Onychomycosis

Answer 45

Fungal infection of nail plate and/or bed
Etiology: dermatophytes or yeast. Risks for developing are older age, swimming, tinea pedis, psoriasis, diabetes, immunodeficiency, genetic predisposition, and living with family members who have onychomycosis
S/Sxs: Nails have asx patches of white, brown, or yellow discoloration and deformity, and may thicken.
Diagnosis: by appearance, KOH microscopy, if negative then nail culture or histopathologic examination of nail plate clippings
DDX: Nail dystrophies: psoriasis, eczematous conditions, senile ischemia (onychogryphosis), trauma, lichen planus, iron deficiency

Question 46

Paronychial infections

Answer 46

periungual infection
S/Sxs: develops along nail margin, becomes painful, warm, erythematous, and swollen. Pus along the nail margin, or beneath the nail.
Diagnosis: by examination.

Question 47

Dermatofibroma

Answer 47

A benign proliferation of fibroblasts usually in adults.
Distribution: most often on lower extremity
S/Sxs: epidermal thickening and hyperpigmentation; small red to brown papule. Does not grow. Usually a solitary lesion but can have up to 10 at one time. Can follow an insect bite or trauma. firm lesions, 0.3 to 1.0 cm in diameter, that are nontender and that dimple when pinched together
DDX: nevi, basal cell carcinoma. if continues to grow consider dermatofibroma protuberans (malignant)

Question 48

Epidermal cyst

Answer 48

epidermally lined cyst containing keratinous material in the dermis
S/Sxs: contains keratin; firm flesh colored moveable nodule in the skin, 1-3 cm w/ often with a central punctum; insignificant, non tender, unless it ruptures.
Distribution: face, base of ears, and trunk
DDX: sebaceous cysts , lipoma, if very firm r/o malignancy or if there are multiples in strange locations r/o Gardner’s syndrome which is epidermal cysts associated with colon cancer.

Question 49

Keloid

Answer 49

excess fibroblastic proliferation following trauma and scarring;
African and Asian descent are most susceptible to the development of keloids
S/Sxs: elevated, shiny, firm protuberant nodule on the site of injury. Can have claw like extensions.
Diagnosis: by appearance.
DDX: Hypertrophic scar- stays confined to original wound margin

Question 50

Lipoma

Answer 50

subcutaneous nodules of adipocytes
More common in women. May have one or more.
S/Sxs: rubbery nodule below dermis that is moveable. Usu asx. Overlying skin is normal. Varies in size. Grows very slowly
Distribution: trunk, forearms, and neck
Dx: Hx & PE. If it is rapidly enlarging, or is firm rather than soft, a biopsy is indicated.
DDX: Epidermal cysts.

Question 51

Nevi (moles)

Answer 51

circumscribed, often pigmented or flesh colored macules, papules or nodules composed of melanocytes.
Diagnosis: H&P, always biopsy suspicious lesions (changing or irregular borders, color changes, painful, or bleeding/ulcerating/itching)
DDX: melanoma, seborrheic keratosis, skin tag, wart

Question 52

Lentigo

Answer 52

hyperpigmented macule due to increased melanocytes; darker, sparser, does not darken or multiply with sun. <4mm

Question 53

Junctional nevus

Answer 53

light brown-black. usually flat but can be slightly raised, pigmented; 1-10 mm; palms, soles, genitals.

Question 54

Compound nevus

Answer 54

light to dark brown, smooth and dome-shaped or papillomatous , may be very elevated; involved epidermis and dermis. 3-6 mm.

Question 55

Intradermal nevus

Answer 55

elevated; flesh colored to brown; smooth, dome-shaped, papillomatous, or pedunculated with a soft, rubbery texture. Can be hairy or warty. Occasionally, they have speckles of brown pigmentation or pseudo-horn cysts 3-6 mm.

Question 56

Halo nevus

Answer 56

pigmented compound or intradermal nevus; surrounded by a halo of depigmented skin; immune phenomenon

Question 57

Atypical/Dysplastic nevus

Answer 57

irregular pigmented nevus from tan to dark brown; indistinct borders, mild asymmetry, can be flat or elevated areas in the same mole; may be genetic; large (>6 mm) and mostly on covered areas; usually see many on the person. Follow these – pts at greater risk for melanoma. See Table on pg 1020 for characteristics of atypical vs. typical moles. Use the “ABCDEF” to assess.

Question 58

Seborrheic keratosis

Answer 58

benign neoplasm resulting in pigmented superficial lesions that usually appear warty, or may be smooth papules generally in older adults.
Distribution: trunk, face, and upper extremities
S/Sxs: “stuck on,’’ warty, well-circumscribed, often scaly hyperpigmented lesions located most commonly on the. Close inspection with a hand lens often will demonstrate the presence of horn cysts or dark keratin plugs. Lesions should almost be able to be picked off with a no. 15 blade. Number of lesions ranges from 1-100’s.
DDX: warts, nevi, melanoma, pigmented basal cell carcinoma.

Question 59

Acrochordon (pedunculated fibroma or skin tag)

Answer 59

Distribution: neck, axilla, groin, under breasts, eyelids
Perianal skin tags are common in patients with Crohn’s disease
S/Sxs: asx, fleshy skin tumor; skin colored or pigmented. Can be pedunculated lesions on narrow stalks. Soft. Can get irritated by friction and bleed
Dx: appearance
DDX: warts, nevi, neurofibromas

Question 60

Basal cell carcinoma

Answer 60

Superficial, slow growing papule or nodule that derives from epidermal basal cells, most common >40
Distribution: face, neck and scalp most common, then shoulders and arms (think sun)
S/Sxs: Highly variable appearance from a small shiny, firm almost translucent nodule to crusty flat lesions to what looks like dermatitis. 3 forms: nodular (60%), superficial (30%), and morpheaform (10%) Nodular usually starts as a papule that slowly grows and develops into a “rodent ulcer” with a shiny pearly border, telangiectasia and a central ulcer . Alternately crust and heal. Superficial has a slightly scaly papule or plaque that is light red in color; the lesion may be atrophic in the center and usually is rimmed with fine translucent micropapules. Morpheaform lesions are smooth, flesh-colored, or very lightly erythematous papules or plaques that are frequently atrophic
Diagnosis: Biopsy
DDX: nevi, seborrheic keratosis, dermatitis, scars, molluscum, squamous cell carcinoma

Question 61

Malignant Melanoma

Answer 61

Arises in melanocytes in skin & mucus mem., eye, or CNS.
S/Sxs: Vary a great deal in appearance but usually pigmented.
Warning SSx of melanoma development in previously benign-appearing mole: use the ABCDE rule and/or the revised Glasgow seven-point checklist (1 major requires referral)
Major:
· Change in size/new lesion
· Change in shape
· Change in color
Minor:
· Diameter >=7mm
· Inflammation
· Crusting or bleeding
· Sensory change
Dx: biopsy
DDX: basal cell carcinoma, seborrheic keratosis, benign nevi/lentigo, dermatofibroma, warts
lentigo-maligna melanoma (15% of melanoma): slow onset and progression. on face or sun exposed areas; 2-6 cm flat, tan or brown macule with darker spots, irregular border and surface, or a plaque with raised indurated edges, colored spots, nodules

Question 62

Superficial spreading Melanoma

Answer 62

(2/3 of melanoma), arise from a pre-existing lesion. diagnosed when smaller than lentigo melanoma. Mostly on women’s legs and men’s torsos. Plaque with irregular raised, indurated, tan or brown areas, with white, red black or blue-black spots.
Nodular: dark protuberant papule or plaque varying in color; grows fast; may not be pigmented

Question 63

Acrolentiginous

Answer 63

Arise in areas of non-hair bearing skin; soles, palms, and subungual skin

Question 64

Squamous cell carcinoma

Answer 64

malignant tumor of epithelial keratinocytes that invades the dermis.
Distribution: sun exposed areas
S/Sxs: Usu on sun exposed areas; Appearance is highly variable, but usu starts as a red papule or plaque with a scaly rough surface, or sometimes is nodular like a wart. Can form cutaneous horns. Eventually ulcerates or bleeds, invades tissue and can metastasize.
Diagnosis: Biopsy
DDX: actinic keratosis, seborrheic keratosis, basal cell carcinoma.