Inflammatory Skin Disease

Question 1

What are the causes of inflammation in eczema?

Answer 1

• inherited abnormalities in skin (barrier defect) leading to increased permeability and reduced antimicrobial function
• inherited abnormality in filaggrin expression resulting in disordered barrier function (filaggrin protein binds to keratin fibres in epidermal cells)

Question 2

What are the different classifications of eczema/dermatitis?

Answer 2

• endogenous (atopic, seborrhoeic, discoid, varicose, pompholyx)
• exogenous (contact (allergic/irritant), photoreaction (allergic/drug))

Question 3

Describe atopic eczema

Answer 3

• itchy inflammatory skin condition which tends to affect the face
• associated with asthma, allergic rhinitis, conjunctivitis, hayfever (atopy)
• high IgE immunoglobulin levels
• genetic and immune aetiology

Question 4

Describe infant atopic eczema

Answer 4

• itchy
• occasionally vesicular
• facial component
• can cause secondary infection
• <50% after 18 months (usually remission by puberty)
• occasionally aggravated by food

Question 5

What are the different complications of atopic eczema?

Answer 5

• bacterial infection (S. aureus)
• viral infection (molluscum (simple pox), viral warts, eczema herpeticum (HSV))
• tiredness, growth reduction, psychological impact

Question 6

What is the appearance of molluscum infection?

Answer 6

Umbilicated papules

Question 7

What is the treatment of eczema?

Answer 7

• emollients (replace barrier seal)
• topical steroids (mainstay of treatment)
• bandages (to stop scratching and hold emollients/topical steroids in place)
• antihistamines
• antibiotics/antivirals (for secondary infection)
• education
• avoidance of exacerbating avoidance (rarely dietary)
• systemic drugs eg. Ciclosporin, methotrexate
• biologics eg. IL4/13 blocker dupilumab

Question 8

Describe contact dermatitis

Answer 8

• precipitated by an exogenous agent
• irritant = direct noxious effect on skin barrier
• allergic = type IV hypersensitivity reaction (cell-mediated)

Question 9

What are the common allergens in contact dermatitis?

Answer 9

• nickel
• chromate (cement)
• cobalt (pigment, dyes)
• colophony (glue, adhesive tape, plasters)
• fragrance

Question 10

Describe seborrhoeic dermatitis

Answer 10

• chronic scaly inflammation of the skin often though to be dandruff
• can affect the face, scalp, eyebrows (rarely upper chest)
• caused by overgrowth of P. Ovale yeast
• can be worse in teenagers (thrives in oily skin)
• severe in HIV/immune dysfunction

Question 11

Describe the management of seborrhoeic dermatitis

Answer 11

• medicated anti-yeast shampoo (antifungal ketoconazole)
• face: anti-microbial mild steroid eg. Daktacort cream
• simple moisturiser
• rare systemic antifungal
• improves with UV/sunlight

Question 12

Describe venous dermatitis

Answer 12

• underlying venous disease affecting the lower limbs
• caused by incompetence of deep perforating veins and increased hydrostatic pressure

Question 13

Describe the management of venous dermatitis

Answer 13

• emollients
• mild/moderate topical steroids
• compression bandaging/stockings (aids flow and valves)
• consider early venous surgical intervention

Question 14

What is psoriasis?

Answer 14

• chronic relapsing-remitting scaling disease which can appear at any age affecting any part of the skin
• plaques of raised areas of inflammation, skin from increased turnover, pitting of nails and onycholysis
• increased keratinocyte proliferation
• T cell mediated autoimmune disease with abnormal infiltration of exaggerated T cells which are releasing inflammatory cytokines such as IFN, interleukins and TNF

Question 15

Describe the causes of psoriasis

Answer 15

• environmental and genetic factors
• associated with psoriatic arthritis, metabolic syndrome, liver disease/alcohol misuse, depression
• PSORS genes and HLA-Cw0602 associated with certain subtypes

Question 16

List the different subtypes of psoriasis

Answer 16

• plaque
• guttate (tear-drop, smaller patches, can indicate risk of developing plaque type)
• erythrodermic (more inflammation)
• flexural/inverse
• palmar/plantar pustulosis
• Koebner phenomenon (at sites of trauma/scars)

Question 17

What is auspitz?

Answer 17

Pinpoint haemorrhages caused by scratching a patch of psoriasis

Question 18

What is the appearance of psoriasis?

Answer 18

Well defined salmon coloured plaque with scaling which can appear white if high turnover of cells, tends to be symmetrical and on extensor surfaces

Question 19

Describe how the management of psoriasis is decided

Answer 19

Depends on:
- severity
- what the patient wants and can cope with
- if they have arthopathy (sore joints, sausage fingers)
- DLQI, PASI and PEST scoring systems

Question 20

Describe the different treatments for psoriasis

Answer 20

• topical creams and ointments (moisturisers, steroids, salicylic acid)
• vitamin D analogues, coal tar, dithranol (slow down keratinocyte proliferation)
• phototherapy light treatment (immunosuppressant, reduces T cell proliferation, encourages vitamin D, UVB used or UVA + psoralen photosensitiser)
• systemic drugs (immunosuppressants eg. Methotrexate, acitretin (retinoid/vit A), dimethyl fumarate, apremilast, biologics eg. Adalimumab (anti-TNF))