Inflammatory Skin Disease

Question 1

Define dermatitis/eczema [1]

Answer 1

itchy inflammatory disorder of the skin

Question 2

Describe the causes/general pathogenesis of dermatitis [4]

Answer 2

1. Combination of genetic, immune and reactivity to a variety of stimuli
2. Inflammation in eczema primarily due to inherited abnormalities in skin, so called “barrier defect”.
   
   • Leads to increased permeability and reduces its antimicrobial function
3. 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.

Question 3

What are the different types of dermatitis? [9]

Answer 3

1. Endogenous:
   
   • Atopic
   • Seborrhoeic
   • Discoid
   • Varicose
   • Pompholyx
2. Exogenous:
   
   • Contact (allergic, irritant)
   • Photoreaction (allergic, drug)

Question 4

What conditions are typically associated with atopic eczema? [4]

Answer 4

1. asthma,
2. allergic rhinitis,
3. conjunctivitis,
4. hay fever (atopy)

Question 5

What are the causes of atopic eczema? [2]

Answer 5

1. High lgE immunoglobulin antibody levels
2. Genetic and immune aetiology

Question 6

What are the clinical features of infant atopic eczema? [6]

Answer 6

1. Itchy
2. Occasionally vesicular (small blisters)
3. Often facial component
4. Secondary infection
5. < 50% still have eczema by 18 months
6. Occasionally aggravated by food (i.e. milk)

Question 7

What are the potential complications of atopic eczema? [5]

Answer 7

1. Bacterial infection
   
   • Staph. aureus
2. Viral infection
   
   • Molluscum
   • Viral warts
   • Eczema herpeticum
3. Tiredness
4. Growth reduction
5. Psychological impact

Question 8

What are the management options for atopic eczema? [9]

Answer 8

1. Emollients
2. Topical steroids
3. Bandages
4. Anti-histamines
5. Antibiotics/anti-viral medication
6. Education for parents/child
7. Avoidance of exacerbating factors
   
   • rarely dietary avoidance/house dust mite etc.
8. Systemic drugs e.g.
   
   • ciclosporin,
   • methotrexate
9. Newest biologic agent:
   
   • IL4/13 blocker - Dupilumab

Question 9

Define Seborrhoeic Dermatitis [1]

Answer 9

Chronic, scaly inflammatory condition

Often thought to be “dandruff’

Question 10

Where can seborrhoeic dermatitis be found? [4]

Answer 10

1. face
2. scalp
3. eyebrows
4. occasionally upper chest

Question 11

What is the cause of seborrhoeic dermatitis? [1]

Answer 11

overgrowth of Pityrosporum Ovale yeast

Question 12

What are the management options for seborrhoeic dermatitis…

1. in the scalp? [2]
2. on the face? [3]
3. in what conditions does it often improve? [1]

Answer 12

1. Scalp - medicated anti yeast shampoo
   
   • i.e. Antifungal ketoconazole - Nizoral, Selsun
2. Face - anti-microbial, mild steroid
   
   • i.e. Daktacort cream → simple moisturiser
3. Often improves with UV/sunlight

Question 13

Describe the pathogenesis of venous (varicose) dermatitis [4]

Answer 13

1. Due to underlying venous disease
2. Affects lower legs
3. Incompetence of deep perforating veins
4. Increased hydrostatic pressure

Question 14

What are the management options of venous (varicose) dermatitis? [4]

Answer 14

1. Emollients
2. Mild/moderate topical steroid
3. Compression bandaging/stockings
4. Consider early venous surgical intervention

Question 15

What are the causes of contact dermatitis? [3]

Answer 15

1. Precipitated by an exogenous agent
   
   • Irritant - direct noxious effect on skin barrier
   • Allergic - Type IV hypersensitivity reaction

Question 16

What are the common allergens associated with contact dermatitis? [5]

Answer 16

1. Nickel
   
   • jewellery,
   • zips,
   • scissors,
   • coins
2. Chromate
   
   • cement,
   • tanned leather
3. Cobalt
   
   • pigment/dyes
4. Colophony
   
   • glue,
   • adhesive tape,
   • plasters
5. Fragrance
   
   • cosmetics
   • creams
   • soaps

Question 17

What is psoriasis? [1]

Answer 17

Chronic relapsing and remitting scaling skin disease which may appear at any age and affect any part of the skin

Question 18

Describe the causes/pathogenesis of psoriasis [6]

Answer 18

1. T cell mediated autoimmune disease
2. Abnormal infiltration of T Cells
   
   • release of inflammatory cytokines incl. interferon, interleukins and TNF (tumour necrosis factor)
   • increased keratinocyte proliferation
3. Environmental and genetic factors
   
   • PSORS genes (e.g. PSORSI, Chromosome 6) and HLA - Cw0602 associated in certain subtypes

Question 19

What are the types of psoriasis? [7]

Answer 19

1. Plaque
2. Guttate
3. Pustular
4. Erythrodermic
5. Flexural/Inverse
6. ?palmar/plantar pustulosis
7. Psoriasis at sites of trauma/scars → Koebner phenomenon (not Auspitz)

Question 20

What is the potential complication of psoriasis that affects up to 20% of patients? [1]

Answer 20

Up to 20% of patients with psoriasis develop arthritis

Question 21

Describe the management options for psoriasis [21]

Answer 21

1. 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
2. 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
3. Systemic drugs/immunosuppressants
   
   • Immunosuppressants
     
     • Methotrexate
     • Ciclosporin
   • Acitretin (oral retinoid / vitamin A)
   • Dimethyl Fumarate
   • Apremilast
4. 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