SKIN PATHOLOGY-2 Flashcards
Covers infectious skin pathology
Describe the morphologic finding shown
Deborah Dalmeida MD

Bowl-shaped lesion with a central depression filled with keratin
The areas of central depression contain viral particles- eosinophilic inclusion bodies known as molluscum bodies or Henderson Patterson bodies.
Deborah Dalmeida MD
Identify the lesion and causative agent
Superficial skin infection; usually face
vesicles and pustules that rupture to form varnish colored
lesions
Deborah Dalmeida MD
Impetigo
S. aureus
Deborah Dalmeida MD
Identify the causative agent
Adult forms infect the skin over the body
breed in clothing
Papular rash, intense itching
Deborah Dalmeida MD
Pediculus humanus corporis (body louse)
Deborah Dalmeida MD
Tuberculoid/Lepromatous leprosy?
Negative lepromin skin test
Absence of granulomas
Numerous acid-fast bacteria within foamy macrophages (MPs)
Deborah Dalmeida MD

Lepromatous leprosy
Deborah Dalmeida MD
Identify the infection and infective agent
Fungal infection of the hairy regions with skin rich in sebaceous glands
Scaly, yellowish, greasy dermatitis
Deborah Dalmeida MD
Seborrheic dermatitis - Malasezzia
Deborah Dalmeida MD
Identify the infection and causative agent
Superfical dermatophytic infection involving body surface
Annular, elevated red, scaly border and clear centers
Deborah Dalmeida MD

Tine corporis - Trichophyton rubrum
Deborah Dalmeida MD
List the toxins involved
Febrile, superficial blistering disease
Deborah Dalmeida MD

exfoliative toxins A and B derived from S. aureus
Deborah Dalmeida MD
Identify the infection
Superficial dermatophytic infection of the groin
Excessive sweating
Non-annular, elevated, scaly border
Deborah Dalmeida MD
Tinea cruris
Deborah Dalmeida MD
Identify the lesion and causative agent
Verrucous papular lesions that are covered by scales
MC sites: fingers, soles

Verucca vulgaris
Human Papilloma virus
Tuberculoid/Lepromatous leprosy ?
Positive lepromin skin test
Hypopigmented macular lesions with complete sensory loss
Granulomas are present, very few acid fast bacilli
Tuberculoid
2 conditions assoc with seborrheic dermatitis

Parkinson disease
AIDS/AIDS-related complex
Type of cellulitis involving the superficial layers of the epidermis and cutaneous lymphatics

Erysipelas
Streptococcus pyogenes
Identify the lesion and causative agent
Superficial skin infection; usually face
dry, honey-colored, crusted (S. pyogenes) lesions

Impetigo
Streptococcus pyogenes
Identify the infection and causative agent
Superficial dermatophytic infection of the scalp
Infects outer hair shaft
+ve Wood lamp
Tinea capitis- Microsporum
Identify the lesion and enunciate the etiology
Prodrome of radicular pain and itching
Rash follows sensory dermatomes

Herpes zoster (shingles)
reactivation of VZV
Identify the causative agent
Adult
Intensely pruritic erosions and burrows in web spaces between fingers, intertriginous areas

Sarcoptes scabiei var. hominis

1. Identify the infection
Tissue protozoa
locates in macrophages/ dendritic cells
Bite–>Papule → ulcers with raised borders
2. What’s the vector?

- Cutaneous leishmaniasis
- Phlebotomus
Identify the lesion and enunciate the mechanism of infection
Painful, pustular lesion
Commonly occurs in dentists

Traumatic implantation of the virus
Identify the infection and causative agent
Superficial dermatophytic infection of the skin
Predominantly affects Upper trunk, extremities; penile shaft
Hypo and hyper pigmented patches
KOH prep shows findings as seen in the attached image

Pityriasis rosea (aka tine versicolor)
Causative agent: Malasezzia globose
Identify the causative agent
Scalp infection
Intense itching
Adult forms of the causative agent lay eggs (nits) on hair shafts

Pediculus humanus capitis (head louse)
Identify the lesion and causative agent
Multiple papules with beginning central umbilication
commonly occurs in children; can be sexually transmitted in adults (common in AIDS)

Molluscum contagiosum
Pox virus
Identify the lesion and causative agent
Fungal infection that presents as an Erythematous rash that occurs in body folds
KOH preparation: pseudohyphae and yeast

Intertrigo

Identify the infection and causative agent
Superficial dermatophytic infection of the scalp
Infects inner hair shaft
−ve Wood lamp
Tinea capitis - Trichophyton tonsurans
Identify the causative agent
Adult forms of this agent live in the pubic hairs

Pthirus pubis (pubic louse, crabs)
Identify the causative agent
Feeds on human blood
Pruritic red papules/wheals occur as an allergic reaction to the anesthetic in the saliva of the organism

Bedbug - Cimex lectularius
Subcutaneous infection in humans who come in contact with infective larvae of the dog or cat hookworms

Cutaneous larva migrans
Describe the Tzanck smear finding in Herpes lesions (Varicella Zoster,gingivostomatitis, herpetic whitlow etc)
multinucleated (MN) squamous cells (SCs) with eosinophilic intranuclear (IN) inclusions, ground glass appearance

Identify the infection and causative agent
Superficial dermatophytic infection
MC in a person with sweaty feet
Macerated scaling rash between one or more toes
Tine pedis- trichophyton rubrum

Identify the lesion and causative agent

Acute inflammation of subcutaneous (SC) connective tissue
Cellulitis
S. aureus