5. Inflammatory dermatoses Flashcards
(47 cards)
What are eccrine and apocrine glands?
- Eccrine - make watery sweat (all over the body)
* Apocrine - make viscous sweat - on axillae and groin
What are the adnexal structures of the dermis?
Pilosebaceous unit
• hair follicle
• sebaceous glands
• erector pili muscle
What is the dermal matrix made up of?
- Collagen
- Elastin
- GAGs
- Blood vessels
- Nerves
Is the papillary or reticular dermis more deep?
Reticular dermis
How are keratinocytes formed?
Basal cell => prickle cell => granular cell => keratinocyte
Which gene mutation is common in eczema patients?
Filagrin gene
What is atopic eczema?
• Dry skin
• Barrier may become defective e.g. filagrin mutation
• Allergens or pathogens can penetrate - sensitisation
• Immune response activated via Langerhans cells
=> acute atopic dermatitis with activation of CD4+ (Th2 response)
=> chronic atopic eczema if left (Th1 response)
• Inflammatory response
• Common, relapsing and remitting
• The first atopic disease to come about in an individual’s life
What is a common sign of the filagrin mutation?
Palmar hyperlinearity
What are the most affected areas in infantile atopic eczema?
Face, arms, elbows, knees
What are the common sites of eczema outbreaks as a child gets older?
Remains on face, but particularly effects the antecubital fossa, popliteal fossa, hands, face and neck
What does acute and chronic eczema look like?
Acute
• Red and slightly blistery
• Often colonised with bacteria
Chronic
• Less red
• Excoriated and lichenified (thickened and accentuation of skin lines)
What bacteria particularly activates eczema?
S. aureus on the skin
How is eczema treated?
- Antibiotics
- Emollients
- Topical and oral steroids
What is eczema herpeticum?
Herpes simplex virus has proliferated on the surface of the skin
What dangerous disease can eczema herpeticum progress to?
Encephalitis => brain damage + death
What is seborrhoeic eczema?
- Just the scalp => dandruff
- Face => redness and greasy, scaly skin
- Mainly affects the nasolabial folds, eyebrows, forehead, chest and back
- Not itchy, but can be sore
- Cause by natural yeast on the skin
How can seborrhoeic eczema be treated?
Anti-dandruff/fungal shampoo, anti-fungal cream, topical steroid
When does seborrhoeic eczema get worse?
- Stress
- Staying up late
- Drinking too much alcohol
- Immunodeficiency
When does seborrhoeic eczema get better?
- No stress
- Sleeping well
- Exposed to sun
What is allergic contact dermatits and what can cause it?
- Very allergic to certain allergens when they come into contact with skin
- Eyelids affected may be due to makeup, preservatives in contact lens fluid and eyedrops
- PPD (pigment in henna) can cause sensitisation
- More likely in patients with atopic eczema
What is discoid eczema?
- Often on legs but can be anywhere
- Discs looking like eczema
- Intervening skin may look normal
- Often just dry skin with secondary dermatitis
What is the treatment for discoid eczema?
- Emollient use
- Topical steroid
- Avoiding soap/shower gel
What is psioriasis?
- Inflammatory dermatoses
- Psoriatic plaques (Raised areas) - salmon pink coloured, well defined, and silvery scaled
- Too many keratinocytes
What causes psoriasis?
- Polygenetic
- More likely to occur in monozygotic twins than dizygotic (shows genetic affect)
- Environmental triggers e.g. infection, stress, drugs
- Pressure and trauma to areas of the skin
- Immune response triggered => overproduction of keratinocytes