The rash is most marked on the cheeks, and is intensely itchy; neither of these features is characteristic of seborrhoeic dermatitis. The rash is typical of atopic dermatitis, the commonest form of eczema in children. In infancy it often starts first on the cheeks. In older children the flexures are commonly affected, as in the next slide.
Cotton bandages moistened with hot water are applied to the affected areas and kept in place for up to 24 hours at a time. The wet wraps are applied daily at first, then the frequency of application may be gradually reduced as skin heals and the itch-scratch-itch habit is controlled. The wet wraps should be re-instituted as soon as the child starts to scratch again.
Pityriasis sicca alba. It is characterised by discrete, hypopigmented patches with a fine branny scale, situated on the face or neck. The cause is unknown. It is possibly a mild form of atopic dermatitis. The patches respond to 1% hydrocortisone ointment or 5% liquor picis carbonis in emulsifying base.
Nummular eczema. They usually occur on the extensor surfaces of the arms and legs as single or multiple lesions on dry skin. The aetiology is unknown. The cause appears to be related to skin dryness rather than to atopy.
Effective treatment includes limiting baths (to avoid skin dryness) frequent lubrication Short courses of potent steroid ointments Control of any associated secondary infection.
Lichen striatus. This is a linear dermatitis of unknown origin, usually self-limiting. and causing no symptoms. It is generally unilateral and affects children between the ages of 5 and 10 years.
In dark-skinned individuals the band-like areas are usually hypopigmented, while in the light-skinned it appears rose- or flesh-coloured. No therapy is necessary and it generally resolves spontaneously in 3-12 months.
Psoriasis vulgaris. This is a common inherited disorder of unknown aetiology, marked by long remissions and exacerbations. Response to therapy frequently varies from individual to individual, and even in the same person at different times.
Using topical keratolytics, such as 5% salicylic acid in vaseline, alternating with tar preparations, such as 5% liqor picis carbonis, or 2-5% crude coal tar in emulsifying base, response is usually favourable.
A Vitamin D3 preparation, Calcipitriol ointment (available as Dovonex) is an effective topical treatment for limited, localised plaques of psoriasis.Topical Anthralin is also effective, but is limited by its staining properties, and is thus reserved for refractory psoriasis.
Outrage psoriasis. This is a variant of psoriasis vulgaris, and generally, but not invariably, follows a streptococcal infection. Topical therapy is the same as for psoriasis vulgaris. Treatment of underlying streptococcal infection often hastens resolution.
Tinea capitis. This is the most common fungal infection of the skin (dermatophytosis) of childhood. Treatment of choice is oral griseofulvin at a dose of 10mg/kg/day for 6 weeks.
occasionally tinea capitis maybe confused with seborrhoeic dermatitis, psoriasis or alopecia areata. Diagnosis of fungal infection can be made with certainty with a potassium hydroxide preparation of hairs and scalp scrapings.
Tinea corporis. This is a superficial fungal infection of the non-hairy skin. The face is particularly affected in children. The lesions tend to be oval with a well-defined border and they spread peripherally as they clear in the centre.
Topical applications of anti-fungal creams are very effective. Either clotrimazole, econozole, ketaconozole or terbinafine could be used and must be applied for 2-3 weeks. The older (but cheaper) benzoic and salicylic acid ointment (Whitfield's) can be used if the others are not available.
Pityriasis rosea. This is an acute, benign, self-limiting condition of unknown cause. Its seasonal clustering and sometimes prodromal symptoms suggest that it is a viral infection. The initial, or 'herald' patch is followed 5- days later by a symmetrical eruption that spares the face and follows the lines of the ribs, so that it has a 'Christmas tree' distribution.
Urticaria. This is a systemic disorder with cutaneous manifestations. The rash consists of irregular wheals which shift in situation. Individual wheals rarely persist longer than 12-24 hours.
Urticaria is referred to as 'acute' if it lasts for less than 6 weeks, and viruses, food or drug allergy are usually the culprits. Urticaria that recurs frequently and lasts longer than 6 weeks is termed 'chronic'. In 80% of patients no cause can be established.
Every attempt should be made to identify the cause and eliminate it if possible.
• The basis of symptomatic treatment is oral antihistamines of which hydroxyzine (Aterax) is cheap and effective.
• Antihistamines should not be stopped prematurely. They should be continued for 1-2 weeks after all signs of urticaria have cleared, and then tapered gradually; this may prevent recurrences and the development of chronic urticaria.
Lichen sclerosis et atrophicus (LSA). This is a condition of unknown aetiology which in children is quite benign. Sexual abuse is often suspected, but this is not the case, and it is not sexually transmitted. The anogenital region is involved in the majority of cases and is characterised by perivulval hypopigmented plaques in an hour-glass pattern. Within the plaques tiny haemorrhages and excoriations are characteristic.
The majority of childhood cases remit with the onset of puberty. Topical corticosteroids (hydrocortisone 1%) and emollient creams offer symptomatic relief. When itching is severe more potent topical steroids may be used for short periods (1-2 weeks).