Dermatitis

Question 1

Definition

Answer 1

1. Interchangeable with eczema
2. Non-specific inflammatory response of the skin
3. Itchy, redness, scaling, weeping

Question 2

Classification

Answer 2

Endogenous

1. Atopic
2. Sebrrhoeic->Greasy scaly around nose, ears and scalp
3. Discoid
4. Asteatoic->cracked skin on lower limbs
5. Venous
6. Hand/foot
7. Lichen simplex->thickened darkened skin due to chronic scratching

Exogenous

1. Irritant contact
2. Allergic contact
3. Photoallergic
4. Phototoxicity

Question 3

General treatment

Answer 3

1. Avoid environmental irritants
2. Improve general skin
   Daily bathing with dispersible oil added to water, lightly dry and +emolient
   Soap/shampoo substitutes
   Avoid scratching
   Minimise overheating
3. Avoid allergic factors
4. Topical treatments
   a. Hydrocortisone 1% on face and flexures
   b. Betamethason valerate 0.02-0.05%, methyprednisilone aceponate 0.1% elsewhere
   c. Betamethasone dipropionate 0.05%, betamethasone valerate 0.1% for more severe
5. Treat infections
   a. Triclosan 2% bath oil diluted
   b. Mupirocin 2% ointment
   c. For widespread- di/dluclozacillin 500mg PO 6 hourly for 10 days
6. Control itching
   Antihistamines
   Wet dressings

Question 4

Adverse effects of topical steroids

Answer 4

1. Loss of dermal collagen: skin atrophy, striae, fragility, easy bruising
2. Telangiectasia
3. Promotion of underlying infection
4. Idiosyncratic reactions->allergic contact dermatitis, perioral dermatitis

Question 5

Preparations in long term chronic dermatosis

Answer 5

Suggested preparations for long-term use of topical corticosteroids for chronic dermatoses are:

1. face and flexures—hydrocortisone 1%, desonide 0.05%
2. trunk—betamethasone valerate 0.02%, methylprednisolone aceponate 0.1%, triamcinolone acetonide 0.02%
3. elbows/knees and palms/soles—betamethasone dipropionate 0.05%, mometasone furoate 0.1%, methylprednisolone aceponate 0.1%.

Question 6

Important considerations when using steroid creams

Answer 6

1. Select appropriate potency
2. Creams for weeping, ointment for dry
3. Need enough to be effective, not to cause side effects
4. Use until controlled, then switch to maintenance.
5. Ask to review if not relieved in expected time
6. Once daily usually adequate
7. Liberal application usually required initially
8. Ensure enough is prescribed
9. Emolient for long term maintenance.

Question 7

Atopic dermatitis in OSCE

Answer 7

1. Examination
   Dermatological
2. Describing lesions
   a. Multiple papules and vesicles on an erythematous base, over the flexor surfaces
   b. These range in size from 1-6mm
   c. There is some evidence of lichenification and scaling, but no evidence of secondary infection or eczema herpeticum
   d. These lesions are consistent with atopic dermatitis
3. Differential
   Other forms of eczema
4. Questions for patients
   FHx asthma, hay fever, eczema

Question 8

Associations in atopic dermatitis

Answer 8

1. Atopic families and individuals
2. Exacerbations associated with
   Allergence
   Infection
   Heat
   Stress

Question 9

Distribution of atopic dermatitis: infancy, childhood, adulthood

Answer 9

distribution
1.ƒƒ infant (onset at 2-6 mo old): face, scalp, extensor surfaces
ƒƒ2. childhood (>18 mo): flexural surfaces, especially antecubital fossae, popliteal fossae, and neck
ƒƒ3. adult: hands, feet, flexures, wrists, face, forehead, eyelids, neck

Question 10

Prognosis in atopic dermatitis

Answer 10

1. Earlier the onset, the more severe

2. 1/3 patients with childhood will continue on to have adult dermatitis

Question 11

Pathophysiology of dermatitis

Answer 11

T cell dysfunction with epidermal barrier dysfunction

Question 12

Is dyshidrionic dermatitis associated with excess sweating

Answer 12

No, but stress may be associated

Question 13

Etiologic association of seborrhoeic dermatitis

Answer 13

Malassezia spp Yeats

Can cause dandruff in adults

Question 14

Management of Seborrhoiec dermatitis

Answer 14

1. Face->Ketoconazole cream + mild steroid cream
2. Scalp-> salicyclic acid in olive oil , ketoconazole shampoo 2%, selenium sulphide (Selsun), zinc pyrithione, steroid lotion

Question 15

Management of stasis dermatitis

Answer 15

1. Compression stocking
2. Rest and elevate legs
3. Moisturise
4. Mid-high potency steroid for inflammation

Question 16

Management of lichen simplex chronicus

Answer 16

1. Treat pruritus->antihistamine, topical antipruritics

2. Topical high potency steroids