i have had the same problem and found i am allergic to grass. i just take an over the counter allergy medicine.
when i mow grass i develope an itchy "hive like" rash on hips/thighs. lasts 2 days. am i alergic to grass? what can do? . only when i mow i can walk in grass and it doesnt bother me. i already take an alergy pill before i mow. these patches itch and burn and cover a large area. . . .