Inherited as an autosomal dominant disorder, this condition is common and affects about 1 person in The relevant gene may be concerned with the production of profilaggrin, a precursor of filaggrin, itself a component of keratohyalin granules.
The dryness is usually mild and symptoms are few. The scales are small and branny, being most obvious on the limbs and least obvious in the major flexures. The skin creases of the palm may be accentuated. Keratosis pilaris is often present on the limbs.
The skin changes are not usually present at birth but develop over the first few years of life. Some patients improve in adult life, particularly during warm weather, but the condition seldom clears completely.
The already dry skin chaps in the winter and is easily irritated by degreasing agents. This should be taken into account in the choice of a career. Ichthyosis of this type is apt to appear in a stubborn combination with atopic eczema.
It can usually be distinguished from less common types of ichthyosis on the basis of the pattern of inheritance and of the type and distribution of the scaling.
None are usually needed.
This is palliative. The dryness can be helped by the regular use of emollients, which are best applied after a shower or bath. Emulsifying ointment, soft white paraffin, E45 and unguentum merck are all quite suit-able (Formulary 1) and the selection depends on the patient’s preference. Many find proprietary bath oils and creams containing urea or lactic acid helpful also (Formulary 1).