Aldehyde, Ketone, Carboxylic Acid Aldehyde: Aldehyde is an organic compound which contain formyl group. This functional group, in its structure R-CHO, consist of carboxyl centre bonded to R group and hydrogen.
1 Infections, bites and stings, infestations, chronic diseases, allergic reactions, sun exposure, and dry skin are among the numerous causes of itching.  Anti-itch creams and lotions containing camphor, menthol, phenol, pramoxine (Caladryl, Tronolane), diphenhydramine (Benadryl), or benzocaine can bring relief.
'Scabies (a tiny mite which lays its eggs in the skin) can cause itch, as can urticaria (also known as hives or nettle rash)'. Treatments to suppress this immune response, such as steroid tablets or cyclosporine, can help suppress the maddening itching.