Can an Allergic Reaction Look Like Bites?

At first glance, it can be difficult to tell if itchy skin bumps are from bug bites or caused by an allergic reaction. Both can cause welts or hives, redness and itchiness, but close inspection of the skin changes can usually help determine the culprit. In addition, allergies can also cause an array of symptoms, sometimes severe ones, that might also impact your lungs, nasal passages, mouth, ears and stomach. Minor cases of hives often resolve without medical intervention, but be sure to see a doctor for ongoing or severe symptoms.

Allergies and Bites

Allergens such as:

• histamine
  
• which cause the classic symptoms of sneezing
  
• runny nose
  
• wheezing --
  
• hives

Also called urticaria, hives caused by allergies are red or skin-colored, raised and often itchy bumps which may occur in clusters, similar to insect bites.

Diagnostic Clues

Potential for Severe Reactions

Sometimes distinguishing between bug bites and allergy-related welts can be a bit more challenging. For example, if you are allergic to the venom of the insect that bites you, the bug bite itself can trigger urticaria -- or sometimes a more severe, life-threatening allergic response called anaphylaxis, which require immediate medical attention. Rarely, an allergic response that starts with skin symptoms, regardless of the trigger, can also be an early sign of a more severe allergic reaction.

Warnings

Minor, short-lived urticaria generally does not need medical evaluation. See a doctor if you have hives that last more than 2 days, if your hives have become open sores, if the hives recur without an obvious cause, or if you have other symptoms such as joint pain, unexplained weight loss, fever, night sweats or swollen lymph nodes. Also, if you experience hives after a bee sting, alert your doctor and seek advice on managing future stings, as the next time your symptoms could be more severe. Alert your doctor to any rashes that are red and target-shaped, or any rashes that are accompanied by a fever. Seek immediate medical attention if you have any symptoms of anaphylaxis, such as difficulty breathing or swallowing, feeling lightheaded or dizzy, or swelling of the lips, throat, face or tongue.

Reviewed by Kay Peck, MPH RD