Itchy dry skin
Bite-sized advice for busy GPs
If a patient presents with an itchy dry skin try to make an accurate diagnosis. Many patients just have 'sensitive skin' – clues include family history, age of onset, if localised or generalised, therapies used and any associated features.
A history, or family history, of the atopic conditions (eczema, asthma and hay fever) along with an itchy flexural rash would point towards a diagnosis of atopic eczema. Recent onset of a new itchy rash affecting multiple family members should alert one to possible scabies.
If a patient presents with dry scaly skin without active inflammation, think of the icthyoses. Icthyosis vulgaris is the most common, is inherited as an autosomal dominant and improves with age. The condition is mild and there is flexural sparing.
Keratosis pilaris are rough papules found on the upper arms and thighs – they tend to be more easily felt than seen. The rash tends to improve in the summer and with age. Treatment includes emollients. An alternative is a 10 per cent urea cream; it can cause stinging but this improves with time.
If an adult develops itchy dry skin it is worth carrying out a general examination and screening for conditions such as lymphoma, anaemia, liver, thyroid and renal disease. Investigations include FBC and ferritin, TFT, LFTs, U&E, RBS and CXR. This information should make best use of referrals.
Elderly patients' skin tends to form a less effective barrier and they easily develop itchy dry skin. Low humidity, central heating, diuretics and the use of antiseptics can contribute to the problem. They develop asteatotic eczema on the shins, with a rather crazy paving appearance.
Patients should wear clothing that does not irritate. Washing with soap and using bubble bath both have an irritant and drying effect on the skin. The patient should use a soap substitute and bath emollient. Rubbing the skin dry tends to irritate and instead it should be patted dry.
Emollients are ideal, have to be applied frequently and need to be prescribed in large quantities, say 500g. Greasier emollients tend to be more effective and less acceptable, so you have to strike a balance. Put simply, the best emollient is the one the patient will use.
Topical steroids or calcineurin inhibitors are used to treat active inflammation. Once this has resolved patients should not continue with steroids to give an emollient effect. Ointment formulations are best for dry scaly rashes, while creams are ideal for acute exudative rashes.
Non-sedative antihistamines are useful when the itch is induced by histamine, as with urticaria. The itch of other conditions such as atopic eczema responds better to sedative antihistamines given at night.
Patients need to be warned about driving and so on.
Thomas Poyner is a GP and hospital practitioner in Stockton on Tees