Hazrat Marjana heard from Umm al-Mu'mineen Sayyida Aisha Siddiqa (may Allah be pleased with her). She was asked whether a muhrim (person in the state of ihram) may scratch his body. She replied: Yes, he may scratch, and he may scratch vigorously, and if my hands were tied and my feet were restrained, I would scratch with that as well.
Hadith Referenceموطا امام مالك رواية يحييٰ / كتاب الحج / 792