Skin disorders

• honey crusts on erythematous base, pus-filled vesicles,
• Staphylococcus aureus (90%) catalase pos coagulase pos GPC in clusters;
• Group Astreptococcus beta hemolytic catalase neg bacitracin sensitive PYR pos Gram
• positive cocci (GPC) in chains

brawny red induration (form of cellulitis) facelower extremity caused by Group A Streptococcus

infant with fragile subcorneal bulla not containing inflammatory cells rupturing easily due to epidermolytic toxins produced by staph infection elsewhere such as otitis or pharyngitis

• erythemaof skin
• super absorbent tampons (or left in too long)
• hypotension
• TSST-1toxin producing S. aureus

• petechial purpuric skin lesions following minor trauma
• hypotension
• necrotizing fasciitis
• Group A Streptococcus

• Type I polymicrobial trauma surgery Staphylococcus aureus;
• Type II Group A Streptococcus;
• Type III Clostridium perfringens or C. septicumgas gangrene

• syphilis
• primary painless punched out chancre rolled borders penile shaft or vulva
• secondary papulosquamous rash on trunk palms, soles lymphadenopathy;
• diagnosis serologic RPR confirmation FTA; plasma cells endoarteritis obliterans; Warthin Starry

• chancroid, multiple painful ragged ulcers irregular borders on penile shaft,
• Gram stain school of fish GNB,
• painful inguinal lymphadenopathy

• granuloma inguinale or Donovanosis,
• spreading beefy red granulation tissue,
• bacilli in monocytes/macrophages in touch prep

• lymphogranuloma venereum,
• small papule on penis 2 weeks later
• fluctuant inguinal nodes with draining fistulous tracts
• stellate microabscesses

• skin lesions with black base (eschar) called ecthyma gangrenosum due to Gram negative bacilli (GNB) in dermal vessel walls with
• thromobosis
• pyocyanin blue green pigment producing
• spa or hot tub folliculitis
• pneumonia in cystic fibrosis patients

acutebacterial meningitis with petechial and larger purpuric skin lesion GNC in vessel walls with swollen endothelial cells, adrenal necrosis Waterhouse Friderichsen syndrome

• cutaneous anthrax most common form with papule, ulceration eventually black eschar,
• capsule spore-forming GPB
• treat with penicillin

• primary cutaneous nocardiosis
• ulcerating skin nodules following lymphatics upper extremity,
• GPB branching and beaded weakly acid fast positive,
• soil organism so history of a hiker or a hunter, thorn, puncture wound,
• sulfonamides for treatment

• a spirochete Borrelia burgdorferi,
• annular bull’s eye target erythematous rash on trunk erythema chronicum migrans;
• headache malaise fever after hiking, walking in park,
• deer tick insect vector of transmission, reservoir of Borreliaburgdorferi white-footed mouse,
• complication destructive monoarticular/polyarticular arthritis small and large joints in Stage 3, neurologic sequelae in Stage 2

• caused by Bartonella henselae
• pyogenic-granuloma like dusky red nodules inguinal region and perirectal, similar lesions on oral mucosa
• history of contact with cats bites or scratches
• HIV positive, often systemic heart, liver, spleen, bone marrow; proliferation of small vessels in dermis, amphophilic granular material between vessels with neutrophils,
• show organism with Warthin Starry stain

• leprosy acid fast bacilli (AFB) lepromatous type with sheets of histiocytes stuffed with AFB creating nodules face neck immune deficiency;
• tuberculoid annular rash with red periphery normal host immunity
• noncaseating granulomas skin with few AFB
• neurotropism

• caused by Human papilloma virus, associated with cervical dysplasia & cancer in some (HPV 16 highest)
• contagious, school age children, larger and many in immunosuppressed transplant patients
• painful deep plantar warts resembling myremecia (anthill)
• hyperkeratosis
• papillomatosis
• wrinkled raisonoid nuclear appearance multinucleation, cytoplasmic clearing called koilocytic change

• due to poxvirus
• pearly papule with central umbilication
• squamous collarette, crater filled with cells having intracytoplasmic granular eosinophilic (Henderson Patterson) inclusion bodies
• disseminated in HIV positive,
• contagious

• STD, multiple vesicles on penile shaft or vulva erosion
• multinucleated syncytial giant cells and ground glass nuclei or red intranuclear Cowdry Type A inclusion
• one of causes of congenital TORCH vesicles on face and trunk

• chickenpox crops of vesicles pruritic in school age child
• painful zoster or shingles in adult reactivation of virus latent in dorsal root ganglia follows dermatome eroded vesicles
• identical appearance as HSV in tissue

• “slapped cheek” rash in school age child plus lacy or reticular rash on extremities;
• risk to pregnant female hydrops fetalis stillbirth
• chronic infection causing red cell aplasia in HIV positive
• hemoglobinopathy intranuclear inclusions in enlarged proerythroblasts

• chronic skin lesions in chronic granulomatous disease
• thrush in HIV pos
• pruritic vaginitis
• invasive esophageal ulcer fungemia
• sausage shaped pseudohyphae with constrictions and blastoconidia

• blastomycosis
• SE US Ohio Missouri River Valley
• broad-based budding yeast
• verrucous skin lesions on extremities and face pyogranulomatous reaction

• sporotrichosis, rose-gardener’s disease
• ulcerating skin nodules along lymphatics
• narrow based cigar or elliptically shaped yeast
• Splendore-Hoeppli antigen-antibody reaction

• AKA ringworm due to superficial skin infection by fungi - Trichophyton, Microsporum, or Epidermophyton
• characteristic ring-like rash with erythematous border
• scalp (tinea capitis sometimes with hair loss)
• face or trunk (tinea corporis)
• groin (tinea cruris)
• feet (tinea pedis),
• PAS or GMS fungi in stratum corneum

• caused by Malassezia furfur
• scaly macules on trunk
• scraping shows “spaghetti and meatballs”

• cutaneous leishmaniasis
• amastigotes in ulcerated nodules
• military personnel served in Iraq, Kuwait, Afghanistan, sandfly vector, also Latin America L. tropica

• due to infestation with head lice
• extremely pruritic, nits (eggs) and lice attached to scalp hair

• due to infestation with crab lice
• sexually transmitted disease
• extreme pruritis involving pubic hair, sometimes eyelashes, eyelids, and chest hair
• crab-shaped lice or nits (eggs) attached to pubic hair

• caused by Sarcoptes scabiei (a mite)
• may be sexually transmitted disease, but may not be
• linear serpiginous tracks or burrows along the sides of fingers, palms, feet, or on glans penis; pruritic papules, palms, around wrists, buttocks, finger webs, glans penis, scrotum, inner thighs
• burrows containing adults mites or eggs in stratum corneum, intense inflammatory reaction in dermis
• highly contagious to health care workers
• Norwegian crusted scabies with a large number of mites

• yellow indurated atrophic plaques on shin
• 55% in diabetics
• extensive full thickness dermal involvement
• layers of chronic inflammation plasma cells
• necrobiotic collagen
• no dermal mucin

• chylomicrons foamy histiocytes in dermis
• uncontrolled diabetes mellitus

• nodule or pustule evolving to necrotic ulcer with ragged
• undermined, violaceous edge, lower extremity,
• systemic disorders (>50%): inflammatory bowel disease (ulcerative colitis/Crohn’s disease),
• myeloproliferative neoplasm, monoclonal gammopathy, hepatitis C
• dysregulated immune system, neutrophil dysfunction, adult

• tightening skin face masklike
• beaklike facies, no wrinkles, sclerodactyly,
• joint contracture
• antibody to Scl-70
• poorer prognosis with diffuse cutaneous pulmonary hypertension and pulmonary interstitial fibrosis

• Langerhans cells longitudinal nuclear groove CD1a pos S100 pos Birbeck granules associated with eosinophils
• pruritic papules on face and neck in infant with Letterer-Siwe/Acute LCH;
• pruritic maculopapular rash on trunk in chronic LCH; mast cells and edema in dermis eosinophils

• plugging of pilosebaceous unit, sebum fatty acids
• Proprionibacterium acnes
• teens pustules red papules

• fish scale like change on shins, very dry skin,
• failure of cells of stratum corneum to separate and shed,
• orthokeratosis absent granular layer

• 20s-30s
• well demarcated white patches, “lip-tip” lips, fingers, toes, trunk, also around orifices, intertriginous zones,
• absence of melanocytes and absence of melanin
• associated with other autoimmune conditions including diabetes mellitus, thyroiditis, alopecia areata, primary biliary cirrhosis

• autosomal recessive (AR),
• defect/absent tyrosinase activity,
• 11q14-q21
• white skin, platinum blonde hair, blue eyes, photophobia/visual problems
• increased risk of skin cancers – squamous cell carcinoma (SCC), basal cell carcinoma, possibly melanoma, melanocytes present but little/no melanin

• oculocutaneous albinism (above findings)
• AKA sea blue (ceroid) histiocytosis, sea blue histiocytes in lungs, skin, liver, spleen, kidney; platelet defects and bleeding
• mutation in APOE gene on 10q23

• oculocutaneous albinism (above findings)
• AR, 1q42-43
• childhood, defective neutrophil function
• have fused bluish-gray lysosomal granules in the cytoplasm of leukocytes,
• staphyococcal and streptococcal infections
• accelerated phase with infection and death

• mucosal pigmentary macules in Peutz-Jeghers and Carney complex,
• no darkening of lesion with increased exposure to sunlight

increased risk of melanoma, including CNS location

• AKA juvenile melanoma (misnomer – NOT melanoma)
• red-brown papule on face of child,
• symmetric, maturation in the dermal component
• proliferation of spindle and/or epithelioid large polygonal cells at d-e junction and in dermis
• blue Kamino bodies with trichrome stain at d-e junction

storiform pattern to fibroblasts in dermis, histiocytes, collagen trapping, epithelial hyperplasia

• finger, hand, trauma,
• rapid growth
• red nodule eroded, squamous collarette,
• lobular proliferation of capillaries,
• inflammatory cells granulation tissue like

• forehead of infant regresses by age 7
• proliferation of capillaries in dermis

• consumptive coagulopathy,
• hemolytic anemia, thrombocytopenia
• massive vascular tumor kaposiform hemangioendothelioma or tufted angioma often involving an entire limb usually lower extremity (LE)

• port wine stain often on face
• brain angiomas ipsilateral
• seizures
• mental retardation
• hypetrophy on port wine side

• lower extremity hemihypertrophy and port wine stain on LE
• varicosities
• risk of infection

• mutation in neurofibromin tumor suppressor gene on 17q ras
• multiple pedunculated skin tumors (neurofibromas)
• large multiple café-au-lait macules
• pigmented Lisch hamartomas
• neurofibroma irregular periphery mix of neuritis, fibroblasts, Schwann cells S100 pos
• 5% risk malignant transformation to sarcoma (malignant peripheral nerve sheath tumor)

• mutation in merlin tumor suppressor gene on 22q
• bilateral acoustic Schwannomas at cerebellopontine angles affecting acoustic 8th cranial nerves
• meningiomas
• Schwannomas composed of Verocay bodies S100 pos

• elderly, face, brown-black papule or nodule (may be pedunculated) which appears “stuck on”
• benign abnormality of basal keratinocytes
• proliferation of immature basal keratinocytes, horn cysts
• sudden appearance (eruption) of many which increase rapidly in size may be indicator of internal malignancy in Leser-Trelat syndrome, often GIT malignancy

• velvety thickening of hyperpigmented skin most notable in flexural areas (axillae, inguinal), intertriginous zones, backs of hands, anogenital
• paraneoplastic manifestation if generalized presentation associated with internal malignancy most often GIT malignancy (stomach, colon) due to TGF-alpha
• Acanthosis nigricans (not paraneoplastic) other important associations obesity, insulin resistance, hirsute female with polycystic ovaries;
• secondary to drug ingestion most notably nicotinic acid (niacin) or oral contraceptives
• hyperkeratosis, papillomatosis, increased melanin in basal layer

• multiple trichilemmomas pink papules on face and lips,
• PTEN mutation on 10q23
• multiple hamartomatous colon polyps, breast CA, thyroid CA, florid fibrocystic disease of breast,
• hypothyroidis acanthosis
• proliferation of cells with clear cell differentiation
• peripheral palisading
• thick basement membrane

• multiple red-yellow papules on sides of nose (adenoma sebaceum actually angiofibromas)
• ash leaf spot, shagreen patch
• low intelligence
• epilepsy
• multiple renal angiomyolipomas
• lymphangioleiomyomatosis in lungs,
• subependymal giant cell astrocytoma (actually probably hamartoma)
• infantile cardiac rhabdomyoma

• AKA squamous cell carcinoma in situ
• same findings as actinic keratosis except that the cytologic atypia is full thickness
• pleomorphic giant cells may also be present
• increased risk with exposure to arsenic with “rain drop” lesion
• marker of internal visceral malignancy in some

• AKA cutaneous T cell lymphoma, pruritic plaques on trunks & extremities
• atypical CD4 positive lymphocytes with markedly infolded cerebriform nuclear contours present at d-e junction and in intraepidermal vacuoles called Pautrier’s “microabscesses”

• pruritic generalized erythroderma with thickened skin,
• similar proliferation of large atypical CD4 positive T lymphocytes called Sezary cells in the dermis
• within intraepidermal vacuoles in Pautrier’s “microabscesses” as well as circulating in peripheral blood, lymphadenopathy due to node involvement

• AKA atopic dermatitis
• toddler with symmetric pruritic vesicles which erode, associated with defective cell mediated immunity, eyelids, face/neck, wrists, flexures of knees & elbows
• intraepidermal edema with spongiosis

• X-linked recessive
• eczema (above findings so intraepidermal edema with spongiosis in skin biopsy) plus recurrent otitis media,
• recurrent infection with Herpes simplex virus
• Varicella zoster virus recurrent pneumonia
• gene located on Xp11.23
• have bleeding problems with epistaxis, petechiae, ecchymoses on legs, small platelet size in blood smear

• linked to type IV delayed type hypersensitivity, requires primary sensitization
• reaction to rubber, metals (nickel), perfumes, nail varnish
• often follows pattern of allergic origin such as rubber in waistband, earlobe, rubber in shoes, face & neck if nail varnis
• intraepidermal edema spongiosis, mix lymphocytes, macrophages, eosinophils

• reaction to drugs (penicillin, dilantin, sulfonamide), infectious agent (HSV, mycoplasma, Histoplasma), Crohn’s
• annular targetoid lesion on palms, dorsa of feet, palms, lower extremities
• skin manifestations range from macules, papules, vesicles, bullae to life-threatening Stevens-Johnson syndrome involving >10% of skin and mucous membranes
• “red dead” keratinocytes, mixed infiltrate of lymphocytes and eosinophils and often fatal Toxic Epidermal Necrolysis with >30% surface area involved

• autoimmune condition, inherited, autosomal dominant (AD) adolescence & young adult
• silvery white scales and plaques with erythematous rim, scalp, extensor surfaces of knees & elbows, sacrum & buttocks
• acanthosis, hyperkeratosis, elongation of rete ridges with clubbing & fusion, neutrophils in parakeratotic layer called Munro’s microabscesses,
• decreased granular layer (hypogranulosis)
• may have asymmetric destructive arthritis with sausage-shaped swelling of fingers (dactylitis), pitting of nails, onycholysis
• new therapy TNF blocker Humari (adalimunab)

• 4 Ps: pruritic, purple, polygonal papules with linear Wickham striae symmetric, wrists, hands, forearms
• intense band-like infiltrate of CD4 positive T lymphocytes hugging the basal layer of the epidermis with destruction of the basal layer
• “sawtooth” appearance of rete ridges, civatte bodies shrunken keratinocytes near d-e junction,
• hypergranulosis direct immunofluorescence (DIF) shows IgM positive civatte bodies at d-e junction & in papillary dermis

• up to 35%
• large violaceous plaque
• trunk, noncaseating granulomas in dermis

• autoimmune disease, young adult female with butterfly shaped erythematous rash involving bridge of nose, cheeks, & upper chest
• history of antiphospholipid antibody syndrome with thromboses and miscarriages, increased anticardiolipin antibodies causing false positive serologic test for syphilis
• positive high titer fluorescent antinuclear antibody (FANA) titer 1:160 or greater, positive anti double-stranded DNA, positive Sm (Smith)
• antigen specific for SLE
• peripheral or rim FANA pattern specific for SLE
• vacuolar degeneration of basal layer, dermal mucinosis, perifollicular/periadnexal lymphocytic infiltrate
• DIF positive granular IgG, IgA, IgM, C3 at d-e junction

• Remember for LE: SOAP BRAIN MD
• S=serositis, O=oral ulcers,A=arthralgia, P=photosensitivity,
• B=blood changes hemolytic anemia/leukopenia/ thrombocytopenia, R=renal involvement (proteinuria, casts), A=ANA, I=immunological anti-Sm
• anti-Double Stranded DNA, N=neurologic signs (seizures, psychosis)
• M=malar butterfly shaped facial rash, D=discoid rash

• middle age, Jews, HLADR4 positive, flaccid blisters on erythematous base with early rupture, oral mucosal erosions, antibodies to desmoglein 3 in desmosomes of keratinocytes, autoimmunity, associated rheumatoid arthritis, pernicious anemia, Sjogren’s, thymoma, myasthenia gravis
• scalp, face, axillae, lower trunk
• suprabasal cleft/bulla due to acantholysis, “tombstone-like” appearance of basal keratinocytes which project into cleft
• DIF fishnet like IgG around and between epidermal cells

• elderly/older than patients with pemphigus vulgaris, less often oral involvement
• inner thighs, flexural forearms, axillae, inguinal region, lower abdomen
• tense large intact bullae
• subepidermal bulla with space containing eosinophils, DIF linear IgG and C3 at the d-e junction

• autoimmune, 2nd-3rd decade, associated with gluten sensitive enteropathy with or without malabsorption, Graves, pernicious anemia
• symmetric, intensely pruritic grouped vesicles on scalp, scapulae, buttocks, skin below elbows & knees
• neutrophils in dermal papillae: DIF shows stippled IgA in dermal papillae
• IgA antibodies to gliadin and reticulin

subepidermal bulla, antibodies to keratin

• reaction to bacteria especially beta-hemolytic group A strep (Streptococcus pyogenes), leprosy, syphilis, virus, chlamydia, fungus
• reaction to drugs (barbiturate, sulfonamide, oral contraceptive, halogens), or systemic (sarcoid, ulcerative colitis, Crohn’s ulcerative colitis)
• painful tender nodules on shins
• septal panniculitus with multinucleated giant cells

painful erythematous nodules on backs of calves, reaction to tuberculosis; septal and lobular panniculitis with granulomas