Inflammatory Skin Disease Flashcards
Define dermatitis/eczema [1]
itchy inflammatory disorder of the skin
Describe the causes/general pathogenesis of dermatitis [4]
- Combination of genetic, immune and reactivity to a variety of stimuli
- Inflammation in eczema primarily due to inherited abnormalities in skin, so called “barrier defect”.
- Leads to increased permeability and reduces its antimicrobial function
- An inherited abnormality in Filaggrin expression considered a primary cause of disordered barrier function.
- Filaggrins are proteins which bind to keratin fibres in the epidermal cells.
What are the different types of dermatitis? [9]
- Endogenous:
- Atopic
- Seborrhoeic
- Discoid
- Varicose
- Pompholyx
- Exogenous:
- Contact (allergic, irritant)
- Photoreaction (allergic, drug)
What conditions are typically associated with atopic eczema? [4]
- asthma,
- allergic rhinitis,
- conjunctivitis,
- hay fever (atopy)
What are the causes of atopic eczema? [2]
- High lgE immunoglobulin antibody levels
- Genetic and immune aetiology
What are the clinical features of infant atopic eczema? [6]
- Itchy
- Occasionally vesicular (small blisters)
- Often facial component
- Secondary infection
- < 50% still have eczema by 18 months
- Occasionally aggravated by food (i.e. milk)
What are the potential complications of atopic eczema? [5]
- Bacterial infection
- Staph. aureus
- Viral infection
- Molluscum
- Viral warts
- Eczema herpeticum
- Tiredness
- Growth reduction
- Psychological impact
What are the management options for atopic eczema? [9]
- Emollients
- Topical steroids
- Bandages
- Anti-histamines
- Antibiotics/anti-viral medication
- Education for parents/child
- Avoidance of exacerbating factors
- rarely dietary avoidance/house dust mite etc.
- Systemic drugs e.g.
- ciclosporin,
- methotrexate
- Newest biologic agent:
- IL4/13 blocker - Dupilumab
Define Seborrhoeic Dermatitis [1]
Chronic, scaly inflammatory condition
Often thought to be “dandruff’
Where can seborrhoeic dermatitis be found? [4]
- face
- scalp
- eyebrows
- occasionally upper chest
What is the cause of seborrhoeic dermatitis? [1]
overgrowth of Pityrosporum Ovale yeast
What are the management options for seborrhoeic dermatitis…
- in the scalp? [2]
- on the face? [3]
- in what conditions does it often improve? [1]
- Scalp - medicated anti yeast shampoo
- i.e. Antifungal ketoconazole - Nizoral, Selsun
- Face - anti-microbial, mild steroid
- i.e. Daktacort cream → simple moisturiser
- Often improves with UV/sunlight
Describe the pathogenesis of venous (varicose) dermatitis [4]
- Due to underlying venous disease
- Affects lower legs
- Incompetence of deep perforating veins
- Increased hydrostatic pressure
What are the management options of venous (varicose) dermatitis? [4]
- Emollients
- Mild/moderate topical steroid
- Compression bandaging/stockings
- Consider early venous surgical intervention
What are the causes of contact dermatitis? [3]
- Precipitated by an exogenous agent
- Irritant - direct noxious effect on skin barrier
- Allergic - Type IV hypersensitivity reaction
What are the common allergens associated with contact dermatitis? [5]
- Nickel
- jewellery,
- zips,
- scissors,
- coins
- Chromate
- cement,
- tanned leather
- Cobalt
- pigment/dyes
- Colophony
- glue,
- adhesive tape,
- plasters
- Fragrance
- cosmetics
- creams
- soaps
What is psoriasis? [1]
Chronic relapsing and remitting scaling skin disease which may appear at any age and affect any part of the skin
Describe the causes/pathogenesis of psoriasis [6]
- T cell mediated autoimmune disease
- Abnormal infiltration of T Cells
- release of inflammatory cytokines incl. interferon, interleukins and TNF (tumour necrosis factor)
- increased keratinocyte proliferation
- Environmental and genetic factors
- PSORS genes (e.g. PSORSI, Chromosome 6) and HLA - Cw0602 associated in certain subtypes
What are the types of psoriasis? [7]
- Plaque
- Guttate
- Pustular
- Erythrodermic
- Flexural/Inverse
- ?palmar/plantar pustulosis
- Psoriasis at sites of trauma/scars → Koebner phenomenon (not Auspitz)
What is the potential complication of psoriasis that affects up to 20% of patients? [1]
Up to 20% of patients with psoriasis develop arthritis
Describe the management options for psoriasis [21]
- Topical creams and ointments
- Moisturisers → help reduce dryness, flaking
- Steroids (reduce autoimmune response, redness, itching, inflammation)
- Salicylic Acid (to dissolve thick dead skin)
- Slow down keratinocyte proliferation
- Vitamin D analogues
- Coal Tar
- Dithranol
- Phototherapy light treatment
- Non specific immunosuppressant therapy
- Can reduce T cell proliferations
- Encourages Vitamin D and reduces skin turnover)
- UV-B light most commonly used
- UV-A with psoralen photosensitiser
- Risks
- Short term burning
- Longer term skin cance
- Systemic drugs/immunosuppressants
- Immunosuppressants
- Methotrexate
- Ciclosporin
- Acitretin (oral retinoid / vitamin A)
- Dimethyl Fumarate
- Apremilast
- Immunosuppressants
- Biologics:
- Adalimumab (anti TNF)
- Ustekinumab (anti IL12/23)
- Most drugs have potent side effects (i.e. liver dysfunction, hypertension, risk of infection) so need to be tailored to patient
