Infectious Disease: Nodules/Plaques

Secondary Syphilis (Treponema Pallidum)

hair loss = Syphilitic alopecia areata

wart papules = Condyloma lata

SSx:

1. Begins 2-8 weeks after disappearance of painless chancre

2. Non-blanching erythematous maculopapular, pustules, squamous/scaly lesions, including the palms and soles

3. Lesions are non-pruritic

4. Mucocutaneous lesions on oral, genital, anal regions

5. Generalized LAD

6. "Moth eaten" hair loss

7. Wart-like moist papules on genitals, oral cavity

Labs:

1. Venereal Disease Research Lab & Rapid Plasma Reagin tests

2. FTA-ABS test is confirmatory for the spirochete

Dx?

Secondary Syphilis (Treponema Pallidum)

Condyloma lata is associated w/...

Verruca vulgaris (common wart) caused by HPV

Hard, elevated keratotic papules w/ a rough, velvet-textured or vegetated surface... tend to occur on hands but can affect any body site

Labs:

1. Altered squamous epithelial cells w/ large pyknotic (dense) nucleus surrounded by a clear perinuclear space

Dx?

Verruca vulgaris (HPV)

The common wart is known as...

Condyloma acuminatum (HPV 6, 11, 16, 18, 31, 33, 35)

Vegetative, cauliflower-surfaced, pedunculated, keratotic papules. Infection almost always occurs on moist surfaces such as genitalia, urethra, perianal and rectal tissue or lips

Labs:

1. Altered squamous epithelial cells w/ large pyknotic (dense) nucleus surrounded by a clear perinuclear space

Dx?

Condyloma acuminatum (HPV)

Anogenital warts are known as...

Verruca plana (flat wart) caused by HPV

Flat-topped, non-scaling, skin colored papules usually on hands, face, and neck... almost always grouped

Labs:

1. Altered squamous epithelial cells w/ large pyknotic (dense) nucleus surrounded by a clear perinuclear space

Dx?

Verruca plana (HPV)

Flat warts are known as...

Verruca plantaris (plantar warts) caused by HPV

Flat to slightly elevated, well-defined, slightly yellow keratotic papules on soles of feet

Labs:

1. Altered squamous epithelial cells w/ large pyknotic (dense) nucleus surrounded by a clear perinuclear space

Dx?

Verruca filiformis (HPV)

Horn-like, think-stalked, keratotic papilloma usually on face or neck

Labs:

1. Altered squamous epithelial cells w/ large pyknotic (dense) nucleus surrounded by a clear perinuclear space

Dx?

Verrucae and Condyloma Acuminatum (HPV)

SSx:

1. Epithelial nodules/benign tumors

2. Multiple subtypes

Labs:

1. Altered squamous epithelial cells w/ large pyknotic (dense) nucleus surrounded by a clear perinuclear space

Dx?

Verrucae

Warts are known as...

Gardasil 9 (for HPV 6, 11, 16, 18, 31, 33, 45, 52, 58)

Verrucae and Condyloma acuminatum can be prevented w/...

Condyloma lata (Treponema pallidum/Secondary Syphilis)

SSx:

1. Smooth, whitish or flesh colored moist papules or nodules on the genitals and oral mucosa and lips and perianal

2. Can also have systemic symptoms

Labs:

1. Spirochete observed

Dx?

Verrucae (HPV)

72 y/o males presents w/ flesh-colored velvety nodules at the base of his neck; histology shows isolated squamous cells w/ pyknotic nuclei

Dx?

Condyloma acuminatum (HPV)

A man and his wife present w/ flesh colored cauliflower like growths on penis and labia. Histology shows isolated squamous cells w/ pyknotic nuclei

Dx?

Condyloma lata (Treponema Pallidum/Secondary Syphilis)

A sexually active adult presents w/ history of fever, LAD, and scaly widespread maculopapular rash and a positive RPR test. Exam reveals white lesions w/ red borders and a few papules on the oral mucosa and several fleshy nodules on the genital mucosa rash and a positive RPR test

Dx?

Kaposi Sarcoma (HHV-8)

SSx:

1. Red/purple vascularized macular patch/plaques and maculopapular nodules

2. Systemic sx as well

History = AIDS, transplants, genetic factors

Labs:

1. Proliferation of spindled endothelial cells

2. Extravasated RBCs

3. Hemosiderin-laden macrophages

4. Inflammatory cells

Dx?

Primary CTB = skin infection

> Inoculation chancre

> Verrucosa cutis

Secondary CTB = has underlying TB in the lung or other organs

> Scrofuloderma

> Miliary TB

> Lupus vulgaris

Primary vs Secondary Cutaneous TB

Primary TB Inoculation Chancre (Primary Cutaneous TB)

Naive (no prior exposure) patient w/ papules/nodules at the site of inoculation... rarely disseminates

Labs:

1. Positive PPD/Mantoux test or IGRA (quantiferon) blood test

2. Acid-fast bacilli

3. Growth not inhibited at 37C

Dx?

TB verrucosa cutis (Primary Cutaneous TB)

Patient w/ prior exposure to TB... a new exogenous inoculation leads to warty lesions... Dx?

Scrofuloderma (Secondary Cutaneous TB)

In a first time patient, a contiguous extension of a focal infection usually a regional node or LAD, lead to firm fistulizing, ulcerating, cold abscesses that scar

Labs:

1. Positive PPD/Mantoux test or IGRA (quantiferon) blood test

2. Acid-fast bacilli

3. Culture on Lowenstein-Jensen medium

4. Growth not inhibited at 37C

5. Abnormal CXR

Dx?

Miliary TB (Secondary Cutaneous TB)

Hematogenous dissemination in IC patient leading to multi organ infection and widespread micro papular or pustule rash that ulcerates and scars

Labs:

1. Positive PPD/Mantoux test or IGRA (quantiferon) blood test

2. Acid-fast bacilli

3. Culture on Lowenstein-Jensen medium

4. Growth not inhibited at 37C

5. Abnormal CXR

Dx?

Lupus vulgaris (Secondary Cutaneous TB)

Reinfection or reactivation of inadequately treated patients leads to dissemination of bacteria to the skin to form soft papules/nodules/plaques usually on the face and neck

Labs:

1. Positive PPD/Mantoux test or IGRA (quantiferon) blood test

2. Acid-fast bacilli

3. Culture on Lowenstein-Jensen medium

4. Growth not inhibited at 37C

5. Abnormal CXR

Dx?

BCG vax

Cutaneous TB can be prevented w/...

M. tuberculosis = growth not inhibited at 37C

M. leprae = growth inhibited at 37C

What's a major difference in the growth of M. tuberculosis vs M. leprae?

Tuberculoid leprosy = mild, confined to skin and peripheral nerves

Lepromatous leprosy = severe, bacteremia, afebrile, more in cool/superficial areas of body

Erythema Nodosum leprosy = severity varies... fever, organ dysfunction and death... major cause of blindness... a reaction to therapy

What are the 3 types of leprosy?

Tuberculoid leprosy (Hansen's Disease)

SSx:

1. Non-contagious

2. Few hypopigmented scaling asymmetrical plaques w/ raised borders, well defined margins and central clearing, hypoesthetic (reduced sensation)

3. Caseating (necrotic) granulomas in peripheral nerves

4. Restricted to butt, extremities, back, and face

Labs:

1. Positive Lepromin skin test

2. Acid fast bacilli/rods in peripheral nerves

3. Growth inhibited at 37C

Dx?

Lepromatous leprosy (Hansen's Disease)

SSx:

1. Contagious

2. Numerous papules and plaques, ill-defined edges, satellite lesions, hypoesthetic (reduced sensation),

3. Foam cell (non-caseating) granulomas surrounded by foamy macrophages

4. Widespread in cooler regions of body

5. Symmetric

6. Afebrile

Labs:

1. Negative Lepromin skin test

2. Acid fast bacilli/rods in peripheral nerves

3. Growth inhibited at 37C

Dx?

Erythema Nodosum Leprosum (Hansen's Disease)

1. Reaction to therapy

2. Febrile

3. Vasculitis

4. Red, hot, painful papules/nodules in crops on face, trunk, and extremities

Which form of Leprosy?

BCG vax or Dapsone

Leprosy/Hansen's Disease can be prevented w/...

Cutaneous coccidioidomycosis

Which endemic opportunistic infection?

Cutaneous blastomycosis

Which endemic opportunistic infection?

Cutaneous histoplasmosis

Which endemic opportunistic infection?

Chagas' Disease/American trypanosomiasis (Trypanosoma cruzi)

SSx:

1. Indurated, erythematous, pruritic, SQ nodule at bite site

2. Romaña's Sign (unilateral periorbital edema)

10-30 years later: widespread painful plaques/nodules, cardiac conditions, digestive disorders (cardiomyopathy, megaesophagus, megacolon, CNS sx)

History = kissing bug bite

Labs:

1. Amastigotes present in macrophages

Dx?

Kaposi Sarcoma (HHV-8)

An injecting drug abuser presents w/ purple-colored maculopapules on his nose that were culture negative. Tests reveal HIV+ and low CD4+

Dx?

Cutaneous TB

A foreign-borne adult presents w/ chronic facial erythematous scaly papules refractory to topical abx... skin scrapings cultured aerobically acid fast rods at 37C... CXR shows few upper lobe opacities... Mantoux test +

Dx?

Leprosy

An Asian migrant presents w/ anesthetic well-defined tinea like plaques on the butt and legs... punch biopsy of skin lesion reveals a few acid fast rods that will not culture on lab media... Mantoux test +

Dx?

Chagas' Disease (T. cruzi)

3 y/o males presents w/ indurated and erythematous lesion on the arm that was culture negative. Edematous swelling of the right eye w/ conjunctivitis and periauricular LAD

Dx?

Cutaneous coccidioidomycosis

57 y/o female w/ history of RA and on injected and oral prednisolone presents at the clinic w/ several scaly slowly progressive erythematous irregular painless non-pruritic ulcerating nodules on her face (nose and upper lip) of 2 month duration... the lesion was culture positive on Sabourauds dextrose agar and showed dimorphic growth in serum... microscopic analysis of the cultures show:

Yeast cells forming large spherules containing endospores and mold of septate hyphae and arthroconidia

Dx?

Cutaneous histoplasmosis

57 y/o female w/ history of RA and on injected and oral prednisolone presents at the clinic w/ several scaly slowly progressive erythematous irregular painless non-pruritic ulcerating nodules on her face (nose and upper lip) of 2 month duration... the lesion was culture positive on Sabourauds dextrose agar and showed dimorphic growth in serum... microscopic analysis of the cultures show:

Yeast cells w/ narrow based buds and mold hyphae w/ microconidia and tuberculated macroconidia

Dx?

Cutaneous blastomycosis

57 y/o female w/ history of RA and on injected and oral prednisolone presents at the clinic w/ several scaly slowly progressive erythematous irregular painless non-pruritic ulcerating nodules on her face (nose and upper lip) of 2 month duration... the lesion was culture positive on Sabourauds dextrose agar and showed dimorphic growth in serum... microscopic analysis of the cultures show:

Yeast cells w/ broad based buds and mold hyphae w/ microconidia

Dx?

Fish Tank Granuloma/Cutaneous mycobacteriosis/Swimming Pool Granuloma (M. marinum)

SSx:

1. Papules turn into painful granulomatous nodules that can ulcerate and scar on extremities and digits

Labs:

1. Acid fast stain: gram positive aerobic-microaerophillic bacillus/rod w/ motility in macrophages

2. Growth inhibited at 37C

3. Photochromogenic plate culture: yellow pigment when grown in light

4. Positive PPD/Mantoux skin test and IGRA/Quantiferon

Dx?

Erysipeloid/Fish Handler's Disease/Swine Erysipelas (Erysipelothrix rhusiopathiae)

SSx:

1. Small red painful macule at inoculation site --> purplish painful nodule

2. Leads to localized cellulitis w/ sharp/well demarcated margins that spreads peripherally in an arciform configuration that resolves centrally w/out desquamation

3. Joint pain in infected hands

4. Can progress systemically w/ fever and septic arthritis and endocarditis

Labs:

1. Isolation of gram positive thin/non-branching filamentous non-motile facultative anaerobic rod bacteria from excision biopsy at 37C

2. Usually a serous exudate

Dx?

Fish Tank Granuloma/Cutaneous mycobacteriosis/Swimming Pool Granuloma (M. marinum)

An adult who works at a seafood processing plant presents w/ wrist joint pain, edema, suppurating ulcer on the pinky, and a few persistent erythematous nodules of the right hand. Culture of the lesion biopsy shows:

Gram positive aerobic acid fast rods that grew well at 30C but very poorly at 37C and produced bright yellow colonies when grown in light. Mantoux test positive

Dx?

Erysipeloid/Fish Handler's Disease/Swine Erysipelas (Erysipelothrix rhusiopathiae)

An adult who works at a seafood processing plant presents w/ wrist joint pain, edema, suppurating ulcer on the pinky, and a few persistent erythematous nodules of the right hand. Culture of the lesion biopsy shows:

Gram positive non acid fast non branching thin filamentous rods that grew at 37C on blood agar aerobically and anaerobically

Dx?

Cutaneous Larva Migrans/Creeping Eruption/Ground Itch (Nematode/Roundworm, dog/cat hookworm larva)

Ancylostoma species

SSx:

1. Transient red papule that becomes erythematous, raised, tubular, wide, and serpiginous

2. Contains serous fluid and a crust may form

3. Intensely pruritic

4. Located in unprotected skin, feet, butt

Labs:

1. No eggs/ova in stool because it is not a human infection

2. Recovery of worm from biopsy is difficult

Dx?

Human Hookworm Disease (Nematoode/Roundworm...Necator americanus or Ancylostoma duodenale) = eggs/ova in stool

or

Strongyloidiasis/Larva currens (Strongyloides stercoralis) = larvae in stool and linear urticaria and potential for hyperinfection (Eosinophilic pneumonitis/Loffler Syndrome, abdominal pain, blood in feces and sputum)

SSx:

1. Pruritic maculopapular, papular, papulovesicular rash, and bullae at infection site (usually feet and hands)

Labs:

1. Either egg or larvae in stool depending on etiological agent

Dx?

Human Hookworm (Necator americanus or Ancylostoma duodenale)

Eggs/ova in stool

Human Hookworm (Necator americanus or Ancylostoma duodenale)

Pruritic rash + eggs/ova in stool

Dx?

Strongyloidiasis/Larva currens (Strongyloides stercoralis)

Pruritic rash + linear urticaria + potential hyperinfection + larvae in stool

Dx?

Cercarial Dermatitis/Swimmer's Itch/Clam Diggers' Itch (Trematode/Flatworm/Fluke)

Saltwater cercarial dermatitis = Clam Diggers Itch

Freshwater cercarial dermatitis = Swimmers Itch

Trichobilharzia stagnicolae

Schistosome = blood fluke

Cercariae = larva

SSx:

1. Pruritic, transient, pink macules or papules that subside 4-48 hours later

2. Develop diffuse pruritic erythematous papules due to Type IV hypersensitivity reaction

History = swimming in saltwater or freshwater where infected snails might be roaming

Dx?

Trichinosis/Trichinellosis (Nematode/roundworm)

Trichinella spiralis

SSx:

1. GI sx first

2. urticaria followed by a maculopapular rash or petechial rash

3. periorbital and facial edema

4. eosinophilia

Hx = ingesting undercooked meat

Labs:

1. elevated creatine phosphokinase and LDH

2. abnormal EMG

Dx?

Human Hookworm

An adult presents w/ pruritic papules or urticaria on back, butt, and feet after walking/lying on human waste contaminated beach. Later, developed fever, epigastric pain, headache, cough, malaise. Tests show eosinophilia and ova in the stools.

Dx?

Human Strongyloides

An adult presents w/ pruritic papules or urticaria on back, butt, and feet after walking/lying on human waste contaminated beach. Later, developed fever, epigastric pain, headache, cough, malaise. Tests show eosinophilia and larva in the stools.

Dx?

Cutaneous Larva Migrans

A child w/ history of barefoot exposure to soil contaminated w/ pet dog feces shows excoriated tubular serpiginous pruritic lesions in skin of the foot. No eggs/ova in the stool.

Dx?

Cercarial Dermatitis

An adult started to itch while swimming in a Wisconsin lake and presents w/ widespread urticaria of the legs and arms w/ associated excoriation.

Dx?

Trichinosis

Adult w/ history of eating undercooked wild boar meat presents w/ urticarial rash accompanied by myalgia, headache and fever. Elevated phosphokinase and LDH correlate w/ abnormal electromyograms. Exam of leftover meat reveals encysted nematode larvae.

Dx?

Pediculosis (lice)

Pediculus humanus capitis = head lice

Pediculus humanus corporis = body lice

SSx:

1. pruritic red macules or papules either on the scalp or shoulders/butt/abdomen

Exam:

1. located at the base of hair shafts, body, and on clothing

2. 6-legged insect

Dx?

Phthiriasis/Pediculosis pubis (Crabs)

Phthirus pubis (pubic lice)

SSx:

1. pruritic, minute, red macules

2. minute red/brown spots in underwear, anogenital hair

Exam:

1. 6-legged insect

Dx?

Scabies (Sarcoptes scabiei)

SSx:

1. erythematous papules/nodules

2. tiny vesicles

3. threadlike burrows

4. favors skin folds

5. more pruritic at night or after showering

Exam:

1. arachnid (8-legged mite)

2. must find a mite, egg, or scybala on a skin scraping of a burrow

Dx?

Bedbug bite

Cimex lectularius & C. hemipterus

SSx:

1. linear biting pattern

Exam:

1. obligate 6-legged ectoparasite requiring blood meals but does not reside on the body

Dx?

Flea bite

Pulex irritans (human flea)

Ctenocephalides species (non human fleas)

SSx:

1. numerous/clusters of pruritic papules and urticaria, frequent central pustule

Exam:

1. 6-legged jumping wingless obligate ectoparasite

Dx?

Trombiculiasis (Chigger bites)

Trombicula/Eutrombicula alfreddugesi

SSx:

1. intensely pruritic maculopapular/papular rash at bite sites

2. can see single inflamed red puncture (stylosome) in each lesion

3. often found in skin folds and where clothing constricts

Exam:

1. Arachnid (8-legged free living crawling mites)

Dx?

Pediculosis

5 y/o presents w/ scalp pruritus and numerous tiny eggs attached to the base of hair shafts.

Dx?

Phthiriasis

Sexually active male presents w/ pubic and anogenital pruritus. Exam reveals nits and lice attached at bases of hair shafts and tiny brown spots on underwear at anogenital site.

Dx?

Scabies

An individual presents w/ persistent pruritus of the hands that gets worse when sleeping or after washing hands. Did not improve with topical steroids. Exam reveals excoriation, reddish brown nodules, and thread-like burrows between the fingers.

Dx?

Bed bug bite

After staying in a hotel in NYC, a lodger notices arrays of erythematous urticarial lesions on the right arm, shoulder, and face.

Dx?

Flea bite

A child has been playing in a dog pen and presents w/ clustered pruritic papules of the lower legs. No insects are found on the child but the child states starting to feel itchy while still playing.

Dx?

Trombiculiasis (chigger bites)

A child, recently playing in tall grass and picking wildflowers, presents later that night w/ intensely pruritic papules along the waistband but does not remember being bitten.

Dx?