Neoplastic Disorders, Infectious Disorders, Cutaneous signs of systemic Conditions Flashcards
What bacterial infections of the skin did we talk about?
Impetigo
Staphylococcal scalded skin syndrome
Cellulitis (Deep pyogenic infection)
Erysipelas
What viral infections of the skin did we talk about?
Verrucae (Warts), Human papilloma virus
Condyloma accuminatum
Herpes Simplex Virus (HSV-1/HSV-2)
Varicella Zoster Virus (Chicken pox/Shingles)
Molluscum contagiosum
What arthropod reactions of the skin did we talk about?
Scabies (Sarcoptes scabiei)
What fungal infections of the skin did we talk about?
Superficial fungus (Dermatophytosis) (Tinea)
Tinea versicolor
What epidermal, melanocytic, lymphoid neoplasms of the skin did we talk about?
Epidermal:
Sebhorrheic Keratosis
Actinic Keratosis
Squamous Cell Carcinoma
Keratoacanthoma
Basal Cell Carcinoma
Melanocytic Tumors:
Acquired and Congenital Melanocytic Nevi
Sporadic and Familial Dysplastic Nevi
Melanoma
Skin Lymphomas
Mycosis Fungoides
What is Impetigo?
With whom is it seen?
What causes it?
How does it present?
Where does it present?
Common superficial bacterial skin infection that is highly infectious.
Mostly seen in childhood or immunocomp adults
Staph aureus most common (Strep pyogenes less)
Small vesicles burst and replaced by thick yellowish crust (Honey colored)
Mouth, nose, extremities most commonly affected.
Impetigo
Histo: Spongiotic epidermis with neutrophilic infiltrate
Clinical: Honey colored thick yelloish dirty crust with margin of erethema
What is Staphylococcal Scalded Skin Syndrome?
In whom is it seen?
What causes it?
Clinical presentation?
Where is it clinically present?
What is it associated with?
Toxin-mediated type of exfoliative dermatitis causing intraepidermal splitting through the granular layer
Seen in infant and children
Caused by 2 exotoxins, ET-A and ET-B (Epidermolytic Toxin) from Toxigenic strains of Staph aureus
Sudden onset of skin tinderness and macular eruption followed by development of large flaccid bullae.
Face, neck, trunk, axillae, groin. MUCOUS NOT INVOLVED
Though rarely in adults, associated with renal disease/inability to clear the toxin and may result in fatal staphylococcal septicemia
Staphylococcal Scalded Skin Syndrome
Histological: Subcorneal splitting of the epidermis, a few acantholytic cells and sparse neutrophils present within blister
What is cellulitis (Deep pyogenic infection)?
Where is it common on the body?
What causes it?
What is the clinical presentation?
Diffuse inflammation of the connective tissues of the skin and/or the deeper soft tissues
More common on legs
Beta-hemolytic streptococci and/or coagulase positive staphylococci
Expanding area of erythema (tender)
Cellulitis (Deep pyogenic infection)
Histologically: In both cellulitis and erysipelas there is marked dermal edema and lymphatic dilatation. Also diffuse infiltrate of neutrophils accentuated around blood vessels
What is Erysipelas?
How does it clinically present?
Where does it commonly clinically present?
What organism commonly causes it?
Distinctive type of cellulitis, a bacterial skin infection involving upper dermis (Superficial cutaneous lymphatics)
Sharply outlined edematous erythematous tender and painful plaques
More common on lower exptremities and in elderly
S. pyogenes is most common
Erysipelas
Histologically: In both cellulitis and erysipelas there is marked dermal edema and lymphatic dilatation. Also diffuse infiltrate of neutrophils accentuated around blood vessels
What causes Verrucae (warts)?
What is the result of warts?
What are the different types of Verruca?
What are the different types of HPV?
What is the pathology?
Human Papilloma Virus (DNA virus)
Self limited, regressing spontaneously w/in 6mo-2yr
Verruca Vulgaris (hands commonly)/Verruca plana (face or dorsal surface of hands)/Verruca plantaris/Verruca palmaris
Low and High risk HPV (verruca caused by low-risk)
Verrucous epidermal hyperplasia/Koilocytosis of upper layer of epidermis/Keratohyaline granules and intracytopasmic aggreg
Verruca (warts)
Verrucous epidermal hyperplasia
Koilocytosis (cytoplasmic vacuolization) of the upper layer of epidermis
Infected cells show keratohyaline granules and intracytoplasmic aggregates
What is Condyloma Accuminatum?
What other HPV types are of note and why?
Clinical presentation?
Sexually transmitted disease caused by HPV 6 and 11
High risk HPV types 16, 18, 31, 33 may increase risk for cancer
Single or multiple papular lesions that are pearly, filiform, fungating, cauliflower, or plaquelike
Condylomata acuminata
Histologically: characterized by marked acanthosis with a broad rounded exophytic growth. Surface of the lesion is hyperkeratotic parakeratotic
What is Varicella-zoster virus and what does it cause?
What causes it?
Pathology of Varicella
Pathology of Shingles
DNA Herpesvirus (lipid-enveloped DS) that causes Chickenpox and Shingles
HSV-1 (common in childhood, lips) and HSV-2 (genitalia, sexually transmit)
Varicella spreads through respiratory route. Rash progresses from macules to vesicles to pustules.
Shingles is recurrence of VZV in adulthood. Unilateral dermatomal distribution in thorax and lumbar
Herpes Simplex and VZV show same histologic changes
Acantholysis of epidermis
Multinucleated keratinocytes with intranuclear inclusions (Cowdry Type A inclusions)
Perineurial and intraneurial inflammation
What is a Tzank Smear
Rapid cytological diagnosis done by making a smear from the base of a freshly opened stain ( of HSV) and staining it with Giemsa stain.
Not as sensitive
What is Molluscum contagiosum?
Where is it seen?
Pathology?
Cutaneous infection caused by large brick shaped DNA poxvirus
Children acquire from close contact (eyelids, face, axilla) and immunocompromised patients (HIV). Penis vulva groin as STD
Pathology: Inverted nodule “crater-like”/Eosinophilic cytoplasmic bodies (Molluscum bodies or Henderson-Patterson bodies)
Molluscum Contagiosum
What is Scabies and how is it spread?
How does it present and where and when?
Contagious caused by the mite Sarcpotes Scabiei, transmitted via prolonged direct human contact and rarely by fomites
Presents as extremely pruritic papulovesicular eruption
Fingers/penis/umbilicus/waistband/axilla/hands
Erupts 4 wks after infestation
Scabies
Fertilized female deposits eggs in burrows in the epidermis. Extend at shallow angle through stratum corneium an dmay reach deeper epidermis.
What is tinea/dermatophytosis?
What are the 3 genera?
How does it present?
What test would you use to identify?
What are the different tineas?
Very common superficial cutaneous infections by fungus
Microsprum/Epidermophyton/Trichophyton
Scaly, erythematous plaques, annular
KOH prep rapid test to find branching septate hyphae
Tinea capitis (scalp)
Tinea corporis (trunk/back)
Tinea barbae (beard)
Tinea cruris (groin)
Tinea pedis (feet)
Tinea
Histologically: variable. Presence of sandwich sign (hyphae sandwiched between normal basket weave stratum corneum and a lower layer of stratum corneum with eitehr orthokeratotic or parakeratosis)
PERIODIC ACID SCHIFF (PAS) STAIN CAN REVEAL THE FUNGUS
What is Tinea versicolor?
Where is it common?
What causes it?
How is it presented?
A common superficial fungal infection.
Tropical climates and in summer months
Malassezia globosa
Multiple irregular areas of hypo or hyperpigmentation which are CIRCULAR AND MACULAR
Tinea versicolor
Histologically: Stratum corneum contains round budding yeasts and short septated hyphae imparting spaghetti and meatballs appearance.
Seen clearly in H&E and PAS preparations
What are Seborrheic keratoses?
Where are they commonly found on the body?
What causes it?
What is a condition involving multiple of these and what is it assoc with
Pigmented papules and plaques with “stuck on” appearance (warty)
Common on face, trunk, and upper extremities
Harbor activating mutations in fibroblast growth factor FGF receptor 3
Leser Trelat sign, associated with internal malignancies (stomach cancer)