Crohn's disease and itchy skin: what to know

Itch does not identify one cause by itself. Someone with Crohn's disease may also have atopic dermatitis, contact dermatitis, psoriasis, hives, scabies, asteatotic eczema, lichen planus or a skin yeast infection. The appearance, location, timing and presence of bowel symptoms help narrow the possibilities.

Crohn's-related inflammation can affect areas beyond the digestive tract, while dry skin, scratching, adhesives, soaps and medicines can create or aggravate a rash. New itch after a medicine change should be recorded rather than assumed to be a flare.

Use a gentle, fragrance-free cleanser and apply a plain moisturiser after bathing. Keep nails short and use a cool compress instead of vigorous scratching. Note whether the itch follows a new product, medicine, food or bowel flare, and photograph changing areas for the appointment.

Do not stop Crohn's treatment without advice. A clinician may examine the rash, review medicines and decide whether testing or a separate dermatology treatment is needed. The right approach depends on whether the skin is dry, inflamed, infected or reacting to contact.

Seek urgent help for itch with facial or throat swelling, breathing difficulty, blistering, skin peeling, widespread purple spots or feeling faint. Contact your care team promptly for fever, painful spreading redness, drainage, yellowing of the eyes or skin, or severe itch that prevents sleep. A new persistent rash deserves review even when bowel symptoms are controlled.

Ask whether the rash looks like a Crohn's-related skin manifestation, eczema, psoriasis, infection or a medicine reaction. Ask which moisturisers or anti-itch treatments fit your medicines, and whether liver, kidney or blood tests are appropriate for persistent generalised itch.