19.1: Inflammatory dermatoses Flashcards
What is the key cell that comprises the epidermis? How are these organized?
Keratinocyte
Layers
What is the stem cell layer of the epidermis?
Stratum basale
What are the five layers of the epidermis, from superficial to deep?
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
(“Come Let’s Get SunBurned”)
What connects the cells in the stratum spinosum?
Desmosomes
Where are the blood vessels in the epidermis?
There are none–only in the dermis
What are the s/sx of atopic dermatitis?
Pruritic, erythematous, oozing rash with vesicles and edema
What parts of the body in particular are affected with atopic dermatitis?
Face and flexor surfaces
What type of hypersensitivity reaction is atopic dermatitis? What other disorders are associated with this (2)?
- Type I
- Asthma and allergic rhinitis
What is the common name for atopic dermatitis?
Eczema
Pruritic, erythematous, oozing rash with vesicles and edema located over the face and flexor surfaces = ?
Atopic dermatitis
Contact dermatitis and atopic dermatitis present similarly. What is the major difference between the two?
Contact dermatitis arises upon exposure to allergens, and is NOT associated with asthma / allergic rhinitis
What type of hypersensitivity reaction is contact dermatitis?
Type IV
What plant classically causes contact dermatitis? Jewelry type?
- Poison ivy
- Ni jewelry
What is the abx that classically results in contact dermatitis?
PCN
What is the treatment for contact dermatitis?
- Removal of offending agent
- Topical steroids
What are comedones?
Whiteheads and blackheads seen in acne vulgaris
What, generally, is acne vulgaris? (hint: what two parts are inflamed)
Chronic inflammation of the hair follicles and sebaceous glands
What is the bacterium that infects in acne vulgaris, and leads to inflammation?
Propionibacterium acnes
Why is it that acne is seen in adolescents?
Increased keratinocytes in the hair shaft and increased sebum production
What is the enzyme that Propionibacterium acnes produces that causes inflammation?
Lipases
What is the role of benzoyl peroxide in the treatment of acne?
Antimicrobial to kill Propionibacterium and thus stop the inflammatory process
What is the role of vitamin A derivatives (retinoids) in the treatment of acne?
Reduces keratin production
What, generally, is psoriasis?
Well circumscribed, salmon-colored plaques with silvery scale
Where on the body does psoriasis usually manifest?
Extensor surfaces and scalp
What fingernail pathology may be seen with psoriasis?
Pitting
Well circumscribed, salmon colored plaques with silvery scale on the extensor surfaces and scalp = ?
Psoriasis
What causes psoriasis?
Excessive keratinocyte proliferation, with a possible autoimmune etiology
What HLA haplotype is associated with psoriasis?
HLA-C
What is the supposed environmental trigger for psoriasis?
Trauma
What is the acanthosis that is seen in psoriasis?
Increased thickness of the epidermis from keratinocyte proliferation
What is parakeratosis?
Excess keratin production, with retained nuclei
What is the significance of elongation of the dermal papillae, and the thin epidermis that lies above it in psoriasis?
Pinpoint bleeds that occur with removing the thin scale seen with psoriasis
What is the name of the collection of PMNs in the stratum corneum?
Munro microabscesses
What is the sign of the pinpoint bleeding from removal of the scaly plaque seen with psoriasis?
Osvet’s sign
What is the treatment for psoriasis? (3)
- Corticosteroids
- UV light with psoralen
- Immune modulating therapy
What is the role of UVA light in the treatment of psoriasis?
Prevent the proliferation of keratinocytes
What are the four P’s of lichen Planus?
- Pruritic
- Planar
- Polygonal
- Purple plaques
What areas of the body are commonly affected with Lichen planus? (3)
- Wrists
- Elbows
- Oral mucosa
What are the superficial findings of Lichen planus?
Reticular white lines on surface
What is the histological characteristics of Lichen planus?
Inflammation of the dermal-epidermal junction, causing a sawtooth appearance
Sawtooth histological appearance at the dermal-epidermal junction = ?
Lichen planus
What infectious agent is associated with lichen planus?
Hep C
