Immuno Inflammatory dermatoses Flashcards
(31 cards)
Layers of the skin
Epidermis, dermis, subcut tissues
Structures found in the demis
pilosebaceous units, blood vessels, sweat glands, sensory nerve endings
Cell types in the epidemis
keratinocyte, Langerhans cells (dendritic cells), Merkel cells (sensory), melanocytes
Layers of the epidermis
stratum corneum lucidum granulosum spinosum basale
Change in shape/ characteristics of keratinocytes as they move up dermis
start cuboidal, become flatter as they reach stratum corneum, lose nucleus and IC structures, become keratinised
Structural arrangement of keratinocytes in stratum cornuem
flat keratinocytes (corneocytes) embedded in lipid (bricks and mortar)
Filaggrin protein
Covered in superfiial sebum layer
Function of keratnocytes
barrier function of skin, innate immmunity
Filaggrin location and function
Filament aggregating protein
Located in stratum corneum, necessary for keratin interaction with lipid envelope
Define atopy
Give examples
tendency to develop hypersensitivity
Atopic eczema, hayfever, asthma
Epidemiology of atopic eczema
Usually affects children up til 10yo (first step of atopic march along with food allergy)
Intrinsic and extrinsic factors affecting atopic eczema pathophysiology
Intrnsic
decreased barrier function of epiermis, atopic activation of innate and adaptive immune cells
Extrinsic
Penetration of exogenous agents eg allergens (house dust mites), irritants and pathogens (staph areus)
Leads to local inflammation
Symptoms of atopic eczema
palmar hyperlinearity
face, elbow, knees itchy rashes in infants
Gene mutation and protein affected in atopic eczema
Filaggrin gene mutation -> filaggrin
decreased barrier function of epidermis (palmar hyperlinearity is a sign of filaggrin gene mutation)
Atopic eczema synonym
dermatitis
Other types of eczema
contact, sebbhoerreic, discoid, herpeticus
Sebbrrhoeic eczema cause and symptoms
overgrowth of malassezia species of yeast on skin with skin inflammation.
Rash has a distinctive distribution including nasolabial folds, eyebrows, scalp, central chest and sometimes axillae and groins.
Often not itchy
Psoriasis symtpoms
red, scaly, plaques, rashes with DEFINITIVE margins
Psoriasis epidemiology
usually affects teens and then 40/50yos
Psoriasis cause
Environmental factors triggering genetic predispositions. Gene mutation in PSOR1. inflammation due to T lymphocyte invasion releasing TNF-alpha
Leads to hyperkeratosis and neutrophil invasion
Bodily distribution of psoriasis
elbows, knees, butt, genitals, umbilicus and lower back
Types of psoriasis
Chronic plaque Guttate Palmoplantar pustulosis Generalised pustular psoriasis Psoriatic arthritis affects approximately 30% of patients with cutaneous disease.
Components of the pilosebaceous unit
hair follicle
sebaceous gland
erector pili muscle
Acne cause
disorder of pilosebaceous unit
Acne pathophysiology
Hyperkeratinisation of the epidermis in the infundibulum of the hair follicle
Accumulation of dead keratinocytes in the lumen of the hair follicle
Increase sebum production stimulated by androgens
Proliferation of propionibacterium acnes within the pilosebaceous unit
Rupture of the inflamed pilosebaceous unit, with further inflammation of the surrounding skin
