Inflammatory skin disease Flashcards
What is dermatitis?
Inflammation of the skin
What is the aetiology of eczema?
- Combination of genetic, immune and reactivity to a variety of stimuli
- Inflammation primarily due to inherited abnormalities (abnormal filaggrin) in the skin called ‘barrier defect’
- This leads to increased permeability and reduces its antimicrobial function
What is the role of filaggrin?
Proteins that bind to keratin fibres in the epidermal cells
What are the types of endogenous eczemas?
- Atopic
- Seborrhoeic
- Discoid
- Varicose
- Pompholyx
What are the types of exogenous eczemas?
- Contact (allergic, irritant)
* Photoreaction (allergic, drug)
What is atopic eczema?
- Itchy inflammatory skin condition
* Genetic and immune aetiology
What is atopic eczema associated with?
- Asthma
- Allergic rhinitis
- Conjunctivitis
- Hayfever
- High IgE immunoglobulin antibody levels
Describe the appearance of atopic eczema
- Occasionally vascular
- Erythema
- Itchy so scratch marks/damage/secondary infection
- Often a facial component
What is the appearance of atopic eczema on darker skin colours?
Baseline darkening/hyperpigmentation in background with white keratinisation/crust
What are the complications of atopic eczema?
- Bacterial infection, most commonly staph aureus
- Viral infection: molluscum, viral warts, eczema herpeticum
- Tiredness due to interrupted sleep due to itch
- Growth reduction
- Psychological impact
What are the managements of atopic eczema?
- Emollient
- Topical steroid
- Bandages
- Antihistamines
- Antibiotics/anti-virals
- Avoidance of exacerbating factors
- Systemic drugs e.g. cyclosporin, methotrexate
- IL4/13 blocker: Dupilumab
What is contact dermatitis?
Inflammation precipitated by an exogenous agent
- irritant: direct noxious effect on skin barrier
- allergic: type 4 hypersensitivity reaction
What immune reaction is Type 1?
- Anaphylaxis
- IgE
- Mast cell
What immune reaction is type 2?
- Transfusion reaction
- IgG
- Cytotoxic
What immune reaction is type 3?
- IgG
- Immune complex
- Serum sickness
What immune reaction is type 4?
- Delayed T cell
* Contact dermatitis
What are the common allergies causing a contact dermatitis?
- Nickel
- Chromate
- Cobalt
- Colophony
- Fragrance
What is seborrhoea dermatitis?
- Chronic, scaly inflammatory condition
- Often thought to be dandruff
- Face, scalp, and eyebrows, occasionally upper chest
- Overgrowth of pityrosporum ovale yeast
- Can be severe in HIV
What is the management of seborrhoea dermatitis?
- Scalp: medicated anti-yeast shampoo
- Face: anti-microbial, mild steroid, simple moisturiser
- Rarely systemic anti fungals
- Often improves with UV/sun
What is venous dermatitis?
- Underlying venous disease
- Affects lower leg
- Incompetence of deep perforating veins
- Increased by hydrostatic pressure
What is the management of venous dermatitis?
- Emollients
- Mild/moderate topical steroid
- Compression bandaging/stockings
- Consider early venous surgical intervention
What is the definition of psoriasis?
Chronic relapsing and remitting scaling skin disease which may appear at any age and affect any part of the skin
What are the age onset peaks of psoriasis?
- 20-30
* 50-60
What causes psoriasis?
•T cell mediated autoimmune disease
•Abnormal infiltration of T cells
- release of inflammatory cytokines including interferon, interleukins and TNF
- increased keratinocyte proliferation
