Dermatitis Flashcards
What is meant by hyperkeratosis?
Increased thickness of the keratin layer
What is meant by parakeratosis?
Epidermal cell turnover occurs more frequently
What is meant by acanthosis?
Increased thickness of epidermis
What is meant by papillomatosis?
Irregular epithelial thickening
What is meant by spongiosis?
Oedema between keratinocytes
Dermatitis is synonymous with eczema. True/False?
True
List some features of the acute phase of dermatitis
Red, erythematous lesions
Oedema
Ooze, scaling, crusting
List some features of the chronic phase of dermatitis
Thickening (lichenification)
Elevated plaques
Scaling
What symptom is always experienced with eczema?
Itch
Name the 7 classifications of dermatitis
Contact allergic Contact irritant Atopic Drug-induced Photosensitive Lichen simplex Stasis dermatitis
What is the basic pathogenesis behind contact allergic dermatitis?
Type 4 (delayed) hypersensitivity
What is the basic pathogenesis behind lichen simplex dermatitis?
Physical trauma to skin, e.g. persistent scratching
List some common causes of contact allergic dermatitis
Nickel
Latex
Topical therapies
Plants
What causes “weeping” in eczema?
Oedema between keratocytes (spongiosis) spills out onto skin surface
What investigation can be used to identify substances causing contact allergic dermatitis?
Patch testing
What is involved in patch testing?
Wells containing allergen applied to skin on back and left for 48-96hrs
Which dermatitis - contact allergic or irritant - is a non-specific reaction?
Contact irritant dermatitis
List examples of things that cause contact irritant dermatitis
Soap
Detergent
Oil
Nappy rash
Contact allergic and irritant dermatitis are easy to distinguish. True/False?
False
Often need to patch test
List some symptoms and signs of atopic dermatitis
Pruritis Scaling Poorly defined erythema Dry skin Flexural distribution
Atopic dermatitis is associated with other atopic diseases. True/False?
True
Secondary infection of atopic eczema is common and occurs due to which organism?
Staph aureus causing crusting
Which virus causes eczema herpeticum?
Herpes simplex virus
What does eczema herpeticum look like? (buzzword!)
Monomorphic, punched-out lesions
What is the UK diagnostic criteria for atopic eczema?
Itch + at least 3 of: Flexural rash History of atopy Dry skin Onset before the age of 2
List step up therapy for eczema
Emollients + topical steroid;
if infection add antibiotics;
phototherapy;
immunosuppressants if systemic upset
What is the most important gene related to atopic eczema?
Filaggrin
What is another name for photosensitive dermatitis?
Chronic actinic dermatitis
What is pompholyx eczema?
Tiny blisters across the fingers, palms and soles
