Skin Pathology Flashcards
Hypersensitivity reaction characterized by targetoid rash and bullae
Erthema multiforme
*Targetoid appearance is due to central epidermal necrosis surrounded by erythema
Indomethacin acts as a nonselective NSAIDs. What are it’s additional modes of action?
- It inhibits motility of polymorphonuclear leukocytes, similar to colchicine.
- It uncouples oxidative phosphorylation in cartilaginous (and hepatic) mitochondria, like salicylates.
Classic location for basal cell carcinoma
Upper lip
NSAIDs have an increased risk of hepatotoxicity when given with __________.
alcohol, barbiturates, anticonvulsants, rifampin
Risk factors for cellulitis
Recent surgery
Trauma
Insect bite
Immunofluorescence highlights IgG surrounding keratinocytes in a “fish net” pattern
Pemphigus vulgaris
Additional functions of celcoxib.
Reduce the numbr of colorectal polyps in people who suffer from FAP
Cellulitis can progress to _________.
Necrotizing fascitis with necrosis of subcutaneous tissues due to infection with anaerobic “flesh-eating” bacteria
Malignant proliferation of squamous cells characterized by formation of keratin pearls
Basal cell carcinoma
- Well-circumscribed, salmon colored plaques with silvery scale, usually on extensor surfaces and the scalp
Psoriasis
treatment for psoriasis
Corticosteroids
UV light with psoralen (destroy keritonocytes)
Immune modulating therapy
Tniea Versicolor
- Caused by Malassezia
- Inhibition of tyrosinase
- Hypopigmentation
- Hyperpigmentation associated with inflammatory response
What effects can be seen if indomethacin is used with vasopressin?
Edema
Hyperkalcemia
Hypernatremia
Hypertension
pemphigus vulgaris is due to _______ antibodies against desmoglein.
IgG
Epidermal hyperplasia with darkening of the skin
Acanthosis nigricans
Regenerative stem cell layer of epidermis
Stratum basalis
Why doesn’t celecoxib affect platelet aggregation?
COX2 selective NSAIDs
malignant proliferation of squamous cells characterized by formation of keratin pearls
Squamous cell carcinoma
Celebrex increases the risk of ________ and _______.
Heart attack and stroke
_________- is the sudden onset of multiple suborrheic ketoses and suggests underlyinf carcinoma of the GI tract.
Leser- Trelat sign
Locations of lichen planus
Wrists, elbow, and oral mucosa
___________ is a precursor leasion of squamous cell carcinoma and presents as a hyperkeratotic scaly plaque, often on the face, back or neck.
Actinic keratosis
- Pruitic, erythematous, oozing rash with vesicles and edema
- Exposure to allergens
- Type IV hypersensitivity
Contact dermatitis
Melanoma risk factors
UVB-induced DNA damage
Prolonged exposure to sunlight
Albinism
Xeroderma pigmentosum
Dysplastic nevus syndrome
__________ is associated with HLA-C.
Psoriasis
Cuase of comedone formation in acne vulgaris
- Due to chronic inflammation of hair follicles and associated sebaceous glands
- Hormone-associated increase in sebum production and excess keratin production block follicles, forming comedones
Autoimmune destruction of desmosomes between keratinocytes
pemphigus vulgaris
most common mole inadults
Intradermal nevus
What are adnexal structures?
Hair shafts
Sweat glands
Sebaceous glands
Presentation for basal cell carcinoma
Elevated nodule with a central, ulcerated crater surrounded by dilated (telangiectatic) vessels
Flesh colored papule with central umbilication
Mollucuscum contagiosum
*Associated with poxvirus
Indomethacin treats….
Gout, RA, and OA
How is SSSS distinguised histologically from toxic epidermal necrolysis?
Separation in toxic epidermal necrolysis occurs ar the dermal-epidermal junction
Histology: inflammation of the dermal-epidermal junction with a ‘saw-tooth’ appearance
lichen planus
most common mole in children
Acquired nevus that begins as nests of melanocytes at the dermal-epidermal juntion (junctional nevus)
Vitiligo
- localized loss of skin pigmentation
- Due to autoimmune destruction of keratinocytes
- Begign squamous proliferation; common in the elderly
- Presents as raisied discoled plaque on the extremities or face
- Often has a coin-like, “stuck on” appearance.
Seborrheic keratosis
Children and teenagers with viral infections, who take NSAIDs, are at risk for __________.
Reyes syndrome
Epidermal layer characterized by keratin in anucleate cells
Stratum corneum
Dysplastic nevus syndrome is __________ (autosomal dominant/autosomal recessive)
Autosomaldominant
How does pemphigus vulgaris present?
- Acantholysis of stratum spinosum keratinocytes, results in suprabasal blisters
- Basal layer cells remain attached to basement membrane membrane via hemidesmosomes
- Nikosky sign
Treatment for acne vulgaris
Benzoly peroxide (antimicrobial)
Vitamin A derivatives (reduce keratin production)
Wickham striae
Reticular while lines on the surface
*Associated with Lichen planus
Pemphigus vulgaris is a type ______ hypersensitivity.
II
___________ is a severe form of SJS characterized by diffuse sloughing of skin, resembling a large burn.
Toxic epidermal necrolysis
*most often due to an adverse drug reaction
Ingestion of large doses of acetaminophen can produce _____________.
N-acetyl-benzoquinoneimine (NABQNE)
*highly reactive intermediate is formed in amounts sufficient to deplete hepatic glutathione
Firm, pink, umbilicated papules due to poxvirus
Molluscum contagiosum
*Affected keratinocytes show cytoplasmic inclusions
Classic location for squamous cell carcinoma
Lower lip
Furunculosis
A furuncle (abscess) forms when a hair follicle and the skin surrounding it become infected.
Autoimmune destruction of hemidesmosomes between basal cells and the underlying basement membrane
Bullous pemphigoid
*IgG antibodies specifically against BP180 component of hemidesmosome
Acetaminophen toxicity
Hepatic necrosis
*Treated with sulfhydryl compounds, which replenish stores of glutathione
Compund nevus
Grows by extension into the dermis
Lentigo maligna melanoma
Radial growth; good prognosis
Epidermal layer characterized by granules in keratinocytes
Stratum granulosum
Patients with high GI and low CV risks should receive a ____________.
cyclooxygenase-2 inhibitor plus a proton-pump inhibitor
In cellulitis, production of ______ leads to crepitus.
CO2
Acral lentiginous
Arises on the palms or soles; often on dark-skinned individuals; not related to UV light exposure
Dermatophytes
Microsporum
Trichophyton
Epidermophyton
Dermatitis herpetiformis has a strong association with __________ disease.
Celiac
Mutation in dysplastic nevi syndrome
CMM1 on chromosome 1
Celecoxib relieves pain and inflammation in what conditions?
OA and RA
Nikolsky sign
Thin-walled bullae rupture easily
Patients with low GI and high CV risks should receive _________.
naproxen
Carbunculosis
A carbuncle is made up of multiple furuncles, and goes much deeper into the skin.
___________ infection produces lipases that break down sebum, releasing proinflammatory fatty acids; results in pustule or nodule formation.
Propionibacterium acnes
Munro microabscesses
Collection of neutrophils in the stratum corneum
*Seen in psoriasis
Components of dermis
Connective tissue
Nerve endings
Blood and lymphatic vessels
Adnexal structures
Pruritic, planar, polygonal, purple papules
Lichen planus
- Pruritic, erthematous, oozing rash with vesicles and edema
- Type I hypersensitivity
- Associated with asthma and allergic rhinitis
Atopic (eczematous) dermatitis
Cause of psoriasis
Excessive keratinocyte proliferation
How does squamous cell carcinoma present?
An ulcerated, nodular mass, usually on the face
Risk factors for basal cell carcinoma
UVB-induced DNA damage
Prolonged exposure to sunlight
Albinism
Xeroderma pigmentosum
Erythematous macules that progress to pustules, usaully on the face; rupture of pustules results in erosions and dry, crusted, honey-colered serum
Impetigo
*Most commonly caused by S. Aureus or S. pyrogenes
Squamous cell carcinoma has the same risk factors as basal cell carcinoma. What are some additional risk factors?
Immunosuppresive therapy
Arsenic exposure
Chronic inflammation
Albinism increases risk for..
Squamous cel carcinoma, basal cell carcinoma, and melanoma due to reduced protectin against UVB
Erythema multiforme with oral mucosa/lip involvement and fever is termed _________.
Stevens-Johnson syndrome
Histology of seborrheic keratosis
Keratin pseudocysts
Histology of basal cell carcinoma
Nodules of basal cells with peripheral palisading
Histology of psoriasis
- Acanthosis (epidermal hyperplasia)
- Parakeratosis
- Munro microabscesses
- Thinning of the epidermis above elongated dermal papillae
Bugs associated with condyloma acuminata
HPV 6 and 11
*Warts, koilocyte
Autoimmune deposition of IgA at the tips of dermal papillae
Dematitis herpetiformis
*presents as pruritic vesicles and bullae that are grouped
Malignancy associated with acanthosis
Gastric carcinoma
*Also associated with insulin resistance
- Gingivostomatitis
- Keratoconjunctivitis
- Herpes labiallis
- herpetic whitlow on finger
- temporal lobe enchephalitis
- esophagitis
- erythema multiform
HSV1
Breslow thickness
The most important prognostic fact in predicting metastasis, depth of extension
Patients with low GI and low CV risks should receive a __________.
traditional NSAID
In SSSS, exfoliative A and B toxins result in epidermolysis of the _________.
Stratum granulosum
What is the most common complication of shingles?
Herpetic neuralgia
How do you test for HSV?
- Viral culture for skin/genitalia
- CSF PCR for herpes encephalitis
- Tsanck test
__________ is a mask-like hyperpigmentation of the cheeks, associated with pregnancy or oral contraceptives.
Melasma
What inflammatory dermatoses is associated with chronic hep C infection?
Lichen planus
Erythema multiforme is most commonly associated with __________ infection.
HSV
*Also associated with Mycoplasma infection, drugs (penicillin and sulfonamides), autoimmune disease and malignancy
Diameter must be greater than _________, to be a melanoma.
6mm
Verruca (wart) is due to _____ infection of keratinocytes.
HPV
*Characterized by koilocytic change
Celebrex contains a sulfonamide derivative as one of its components, which are well known to cause ___________.
Stevens-Johnson syndrome
___________ is a well-differentiated squamous cell carcinoma that develops rapidly and regresses spontaneously.
Keratoacanthoma
Epidermal layer characterized by desmosomes between keratinocytes
Stratum spinosum
Common location for acanthosis nigricans
Axilla; groin
How does keratoacanthoma present?
Cup-saped tumor filled with keratin debris
Due to an increased # of melanosomes
Freckle (Ephelis)
*melanocytes are NOT increased
Treatment for basal cell carcinoma
Surgical excision
*metastasis is rare
Nodular melanoma
Early vertical growth; poor prognosis