13.5.1 Contact Dermatitis
Is a delayed hypersensitivity reaction following skin coming into contact with a particular chemical. This may be a dye, perfume, rubber, nickel, drugs, skin preparations containing lanolin, iodine, antihistamines, neomycin etc.
Diagnostic Criteria
- Red papulo-vesicular rash with ill-defined margins
- Itching, which may be severe
- Dry, cracked, scaly skin, if chronic
- Blisters, draining fluid (weeping) and crusting, with severe dermatitis
- Swelling, burning or tenderness
Non-Pharmacological Treatment
Avoid contact with allergen
Pharmacological Treatment
C: Betamethasone valerate 0.025% cream/ointment 12 hourly for two weeks
Note: Super potent and potent topical corticosteroids are first-line pharmacologic therapy. A single application with occlusion at night is often more effective than multiple daytime applications
13.5.2 Atopic Eczema
It is a dermatitis/Eczema on a background of atopy. Hence there is often a personal or family history of atopic disease (asthma, hay fever or atopic dermatitis).
Diagnostic Criteria
The clinical form may differ according to age:
Infantile eczema (“milk crust”)
- Usually appears at 3 months of age with oozing and crusting affecting the cheeks, forehead and scalp.
IMPORTANT: If generalized exfoliative dermatitis develops. Refer to a higher level facility for possible specialist care
Flexural eczema:
- Starts at 3–4 years,
- Affecting the flexural surfaces of elbows, knees and nape of the neck
- Thickening and lichenification
- Intense itching, particularly at night
Note: Eczema may evolve through acute (weepy), subacute (crusted lesions), and chronic (lichenified, scaly) forms.
Non-Pharmacological Treatment
- Education and explanation
- Remove any obvious precipitant e.g. skin irritants or allergens (avoid irritants e.g. medicated soap, wool and extremes of temperature).
- Avoidance of irritants/allergens
- Generous use of emulsifiers (skin moisturizers)
- Bath oils/soap substitutes
Pharmacological Treatment
A: Promethazine (PO) 25mg at bedtime increased to 50mg if necessary
OR
A: Cetirizine 10mg (PO) once daily
OR
C: Loratadine 10mg (PO) once daily
AND
B: Hydrocortisone 1% ointment 12 hourly (if mild disease, or on delicate skin surfaces)
OR
C: Betamethasone valerate 0.025% cream/ointment 12 hourly for two weeks
For severe cases
- Adjunct therapies
- Sedating antihistamines,
- Occlusive bandaging and
- Oral antibiotics
- Short course of systemic steroid (eg Prednisolone) therapy
Note: Never use topical antihistamines
IMPORTANT
- Treat any infection (usually bacterial, but occasionally viral).
- Choice of skin preparations depends on whether lesions are wet (exudative) or dry/lichenified (thickened skin with increased skin markings).
- If eczema is “weepy”, use saline baths or bathe in: Potassium permanganate 1:4000 (0.025%) solution once daily for 2-4 days until dry. Where large areas are involved give a course of antibiotics for 5-10 days (as for impetigo)
- After the lesions have dried, apply an aqueous cream for a soothing effect. A topical corticosteroid cream may be useful in the acute phase. Use the mildest topical steroid application possible.
- Start with mild topical steroid cream for wet lesions, and use ointment for dry skin lesions. Apply thinly, initially, two times a day.
- If the skin starts scaling (condition becomes chronic), add/apply an emollient such as: emulsifying ointment or liquid paraffin.
CAUTION: For lesions on the face use only 1% hydrocortisone cream, unless otherwise prescribed by a Specialist
Note: Potent topical corticosteroids may cause harmful cutaneous and systemic side effects especially if the use is prolonged or involves extensive body surface. Striae, acne, hyperpigmentation and hypopigmentation, hirsutism and atrophy may result. Therefore, avoid long term use; don’t use on weepy or infected skin. Advise patients NOT to use them as cosmetics (eg for skin lightening purposes)
Example of Classes of Topical steroids;
Very Potent (0.05% clobetasol proprionate), Potent (0.1% betamethasone valerate), Diluted Potent (0.025% betamethasone valerate), Moderately Potent (0.05% clobetasol buterate), Mild (1% hydrocortisone)
