Itchy bumps on the outer thighs, consider the possibility of insect bite dermatitis, eczema, herpes zoster, as follows: 1, insect bite dermatitis: mainly due to mosquito bites and local metamorphosis; 2, eczema: is due to wear cashmere or wool lining pants, and allergic reactions, treatment can be oral loratadine capsules, with compound glycopyrrolate capsules, topical hydrocortisone butyrate ointment Herpes zoster: usually occurs on the outer side of the unilateral thigh, in addition to small bumps, can also appear in clusters of small blisters, accompanied by itching or pain, in the treatment can be oral valacyclovir granules, as well as methylcobalamin capsules, external use of ganciclovir ointment 2 times / day to apply.