Occasionally people with AD notice a worsening of their condition when exposed to airborne allergens, such as pets or dusty rooms. An allergy to dust mites (tiny organisms present in household dust) may worsen AD in some people. As with foods, positive scratch and blood tests are not very reliable for diagnosing an allergy to airborne substances. Research is being done on a “patch test” in which the suspected allergen is placed on the surface of the skin under a protective bandage. For now, however, the best approach is still the trial and error challenge method, exposure and avoidance under physician observation. Allergy shots do not seem helpful for people with AD. In some cases, the AD actually worsens during allergy shot therapy, even as the allergy symptoms are improving.