What should you know about cows milk allergy rash?

An allergic reaction to cow's milk may produce raised itchy welts, flushing or swelling soon after exposure. Some reactions also involve vomiting, coughing, noisy breathing or a change in alertness. A delayed reaction can be harder to recognise and may involve ongoing skin or digestive symptoms.

Many other conditions present with a rash. Atopic dermatitis can cause dry itchy patches, while contact dermatitis follows skin exposure to an irritant or allergen. Heat rash, intertrigo, psoriasis, ringworm, scabies and a drug rash have different patterns and management needs.

Write down what was eaten, the amount, the time symptoms began, the rash pattern and any breathing or digestive symptoms. Take clear photographs and arrange an assessment with a clinician experienced in food allergy. Do not use a home food challenge to test the theory.

Do not remove dairy from a child's diet for a prolonged period without a medical plan, because nutrition and suitable substitutes need attention. A clinician may advise supervised testing or an elimination and reintroduction plan. Keep the skin comfortable with bland moisturiser and avoid fragranced products while the cause is being assessed.

Seek emergency help for trouble breathing, throat or tongue swelling, repeated vomiting, faintness, unusual sleepiness, pale or blue skin, or symptoms affecting more than one body system after milk exposure. For a rash that is painful, blistering, rapidly spreading or associated with fever, arrange prompt medical review.

Ask whether the timing and rash type fit an allergy, whether another rash condition is more likely, how to maintain nutrition during any trial, and what emergency action plan should be followed after accidental exposure.