Why does graft-versus-host disease cause persistent itching?

After an allogeneic transplant, donor immune cells can react against the recipient’s tissues. When the skin is involved, inflammation may cause dryness, a rash, scaling, sensitivity, or thickened areas. A weakened skin barrier loses moisture more easily and allows everyday friction, heat, and products to provoke stronger sensations. Scratching then creates small breaks that increase irritation and can invite infection, forming an itch-scratch cycle.

Skin involvement can occur with other graft-versus-host disease symptoms. The appearance and distribution of a rash, changes in the mouth or eyes, bowel symptoms, and liver-related changes help the transplant team judge the pattern. Persistent itching can also have causes unrelated to graft-versus-host disease, so do not change immune medicines based on itch alone.

Tell the transplant team about new or worsening itch, even when the skin looks fairly normal. Use the moisturiser or prescribed treatment they recommend, apply it gently after washing, and choose lukewarm water with a mild, fragrance-free cleanser. Keep nails short, wear loose soft clothing, and use cool measures rather than vigorous scratching. Avoid starting steroid creams, antihistamines, supplements, or herbal products without checking first because they may affect treatment or mask a changing rash.

Contact the transplant team urgently for rapidly spreading redness, blistering, peeling, painful skin, fever, drainage, or marked tenderness. Seek immediate help for breathing difficulty, facial swelling, faintness, or confusion. Report yellowing of the eyes, dark urine, severe diarrhoea, or inability to drink as these may signal broader illness requiring prompt review.

Ask whether the itch fits skin graft-versus-host disease, which products are safe for your skin, and how to distinguish treatment irritation from infection. Ask what symptoms should trigger a same-day call and whether any current medicines could worsen dryness or drowsiness.