Diseases 1 Flashcards
Psoriasis
- definition
- risk factors
- triggers
- chronic proliferative inflammatory, relapsing skin disorder
- genetic predisposition, family history –> HLA-encoding genes
- acute and chronic infections, diabetes and obesity, alcohol consumption, smoking, stress, contact irritants, allergens, medications
Psoriasis
-pathogenesis
- Accelerated proliferation of epidermis (acanthosis) and abnormal differentiation of keratinocytes (parakeratosis)
- Proliferation of capillaries
- Immunologic inflammation
- two imp. cytokines: IL-12 (induces Th1) and IL-23 (induces Th17)
Psoriasis
-classification (4)
- Psoriasis vulgaris - most common - guttate psoriasis (severe), plaque like psoriasis (slow growing)
- Inverse psoriasis
- Pustular psoriasis - white pustules (blister of non-infectious pus) surrounded by red skin, most often in the hand
- Erythrodermic psoriasis
- Plaque psoriasis
- Guttate psoriasis
- Erythrodermic psoriasis
- Inverse psoriasis
- symmetrically distributed, thick, scaly, erythematous lesions, itchy and painful, they can crack
- small dot like lesions, occurs mainly in children and adolescents after streptococcal infection
- generalized erythematous lesions with diffuse scaling, can cause severe itching and pain
- very red lesions, mainly affects skin folds and flexural creases of large joints, appears as smooth and shinny
Koebner phenomenon psoriasis
-isomorphic response to irritation –> incisions, scratching lesions, UV radiation, tattoos
Psoriasis
-diagnosis (4)
- anamnesis
- physical examination - Auspitz sign triad (small, pinpoint bleeding, no scales), Koebner phenomenon, PASI index
- lab tests - CRP, liver enzymes, serological tests
- radiography, skin biopsy
Psoriasis
-treatment
- anti-inflammatory
- anti-hyperproliferative
- local medications - keratolytics, emollients, vitamin D3, corticosteroids, local retinoids
- phototherapy - sunbathes, UVB
- systemic treatment - methotrexate, antibiotics, biological therapy
Lichen planus
- definition
- triggers
- pathogenesis
- inflammatory, t-cell mediated disease that involves the dermal-epidermal junction
- liver problems, diabetes, viral infections, stress, drugs, autoimmune processes
- autoimmune CD8+ T cell response against the epidermal basal later keratinocytes, causing apoptosis
Clinical features - 5 P’s
- Planar - rash is flat
- Polygonal - rash has multiple sides
- Papular - less than 5mm in diameter
- Purple color
- Pruritic
Lichen planus
-clinical features (4)
- Wickham’s phenomenon - a network of milk white lines on the surface of merging papules
- Koebner phenomenon - isomorphic irritation effect
- mucosa (more common), nail or scalp
- super itchy
Lichen planus
- diagnosis
- treatment
-clinical features, histology, punch biopsy, dermoscopy –> Wickham’s sign
- local: corticosteroids, anesthetic liquid for moth, immunomodulators
- phototherapy
- systemic: corticosteroids, anti-histamines, antibiotics
Contact dermatitis
- definition
- classification
-skin inflammatory reaction to substances that come in contact with the skin
Irritant contact dermatitis - most common - caused by direct contact with irritant substance. No sensitization is required.
-acute, subacute, chronic
Allergic contact dermatitis - caused by antigens that elicit hypersensitivity reaction in area of contact = requires previous exposure and sensitization
-acute, chronic
Contact dermatitis
-etiology
Irritant contact dermatitis - physical and chemical irritants, direct tissue damage
-acids, alkalis, organic solvents, detergents
Allergic contact dermatitis - immunologic mechanism, T cell mediated
-cosmetics, metals, fragrant substances, preservatives
Contact dermatitis
-Clinical features
Acute - erythema, edema, vesiculations, papules, erosion, crusting, scaling
Chronic - erythema, less vesicles, papules, scaling, fissures, lichenification
- sharp margination, stickly confined to exposure site –> mostly hand and forearms
stages: edema –> bullae –> erosions –> crusts –> scales
Contact dermatitis
- diagnosis
- treatment
- anamnesis, inspection, lab tests - patch test
- elimination of the allergen, restore skin barrier with emollients, reduction of inflammation, reduction of itching - anti-histamines, prophylaxis
Atopic dermatitis
- definition
- etiopathogenesis
-chronic, inflammatory skin disease
- allergic: IgE and non- IgE associated
- non allergic: genetic predisposition, filaggrin deficiency (less binding of water –> skin barrier dysfunction –> immune dysregulation)
Atopic dermatitis
-clinical features
- infantile type - wet forms - vesicle, erosions. Location: face, trunk, extensor surface of arms/legs
- childhood type - dry forms - papules, lichenifaction, excoriations. Location: face, lateral aspects of neck, nuchal region, flexor surfaces of arms/legs
- atopic diathesis = atopic triad –> atopic dermatitis, allergic conjunctivitis/rhinitis, allergic asthma
Atopic dermatitis
- diagnosis
- treatment
-anamnesis, inspection, path test, prick test, blood test, skin biopsy
- elimination of the allergen, restore skin barrier with emollients, reduction of inflammation, reduction of itching - anti-histamines, prophylaxis
- phototherapy
Seborrheic Dermatitis
- definition
- etiopathogenesis
-chronic inflammatory skin disease affecting seborrheic body sites (head, face, upper trunk)
I. Malassezia infection
II. Immunologic mechanisms
III. Hyperproliferative changes
Seborrheic Dermatitis
-clinical features
in infants - pink squamous patches and/or plaques, scales are yellow/greasy, oily looking thick fissured crust on scalp
-diaper region, face, neck, chest, retroauricular folds
in adults - pink squamous patches and/or plaques. Scales are yellow and greasy
Seborrheic Dermatitis
- diagnosis
- treatment
-anamnesis, presentation, culture
I. loosening of scales - keratolytic, emollients
II. inhibition of yeast colonization - anti-mycotics
III. prophylaxis
IV. reduction of inflammation
V. phototherapy
Diaper dermatitis
- definition
- etiopathogenesis
-inflammatory skin disease affecting regions covered by diaper
- mechanical impact of diaper, wet environment
- feces contain urease –> break down urea into ammonia –> increase pH of skin –> pH activates fecal enzymes –> breakdown of proteins and lipids in the skin –> keratinocytes release cytokines –> inflammation
Diaper dermatitis
-clinical features
- erythematous squamous patches and/or plaques in the diaper area
- vesicles, oozing, crusts
Diaper dermatitis
- diagnosis
- treatment
-anamnesis, clinical presentation, culture
- frequent diaper change, local anti-mycotics, emollients, weak potency corticosteroids
- prophylaxis: zinc cream
