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Allergy / Immunology

An allergy is a disorder of the immune system.  Allergic reactions occur when your immune system reacts to normally harmless substances, called allergens, in the environment.

Common allergens include:

  • Airborne allergens (dust, pollen)
  • Drugs (like codeine or penicillin)
  • Food allergens (peanuts, shellfish)
  • Insect stings (bees)
  • Latex (which is often in many household items)
  • Metals (nickel)
  • Pet dander
  • Plants (poison ivy, poison oak)
  • Seasonal allergies strike as the environment changes

Mercyhealth allergists have the expertise to test you for allergies and intolerances, prescribe treatment and provide follow-up care.

The symptoms of allergies differ from person to person and different allergies can cause different symptoms from the very mild to the very severe: coughing, sneezing, itching, hives, pain, and swelling, just to name a few. Some people get headaches or nausea. Allergies can affect so many parts of your body too, from making your eyes water to your feet itch.

Because allergies manifest themselves in such different ways having an array of effects, there are many treatment options your allergist can prescribe that work better than over-the-counter remedies. There are prescription nasal sprays and eye drops too. Your physician may be able to help you with allergy shots and offer advice on avoiding your particular allergens.


Find a Provider

Providers available for this service:


Mercyhealth Barrington

500 W. Hwy. 22
Barrington, IL 60010

Phone: (847) 381-3000

Mercyhealth Crystal Lake East

390 Congress Pkwy.
Crystal Lake, IL 60014

Phone: (815) 455-0850

Mercyhealth East

3524 E. Milwaukee St.
Janesville, WI 53546

Phone: (608) 756-7100

Mercyhealth Hospital and Medical Center–Walworth

Hwys. 50 and 67, N2950 State Rd. 67
Lake Geneva, WI 53147

Phone: (262) 245-0535
Toll-Free (800) 637-2901

Mercyhealth Rockton Avenue, Building 1

2300 N. Rockton Ave.
Rockford, IL 61103

Phone: (815) 971-2000
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