Hives can develop when experiencing mononucleosis (mono). Understanding why this occurs and what to do is important.
Understanding the Connection Between Mono and Hives
Hives, or urticaria, in individuals with mononucleosis most frequently arise as a reaction to certain antibiotics, rather than the viral infection itself. Mononucleosis is caused by the Epstein-Barr virus (EBV), a viral agent that does not respond to antibiotic treatment. Antibiotics, particularly amoxicillin or ampicillin, are sometimes mistakenly prescribed for mono, often due to a misdiagnosis or to treat co-occurring bacterial infections like strep throat.
When amoxicillin or ampicillin is administered to someone with an active EBV infection, a widespread skin rash can develop. This reaction is not typically a true allergic response, but rather a common side effect unique to the interaction between these specific antibiotics and the Epstein-Barr virus. The exact mechanism involves a transient virus-mediated immune change that alters the body’s tolerance to the antibiotic. While early reports suggested a very high incidence, more recent studies indicate that this rash occurs in about 30% of patients with mono who take amoxicillin. Less commonly, the mono infection itself can directly trigger an immune response leading to hives, even without antibiotic exposure.
Recognizing Mono-Related Hives
Hives linked to mononucleosis, especially those caused by antibiotic reactions, appear as itchy, red welts or bumps on the skin. These lesions vary in size and shape, appearing as flat, discolored areas and small, raised bumps. The rash commonly affects various parts of the body, including the trunk, arms, face, neck, and sometimes the palms and soles.
Onset often occurs within 2 to 10 days after starting the antibiotic, or even after discontinuing the medication. Unlike some allergic reactions, the rash from amoxicillin in mono is not associated with severe systemic symptoms. The hives resolve within a week of discontinuing the antibiotic.
Managing Hives and Seeking Medical Advice
If hives appear with mono, especially after taking antibiotics, contact a healthcare provider. If the rash is suspected to be from an antibiotic, the medication should be discontinued, but only under medical guidance. General management strategies for hives include taking over-the-counter antihistamines to reduce itching and applying cool compresses to the affected areas.
Seek immediate medical attention if you experience signs of a severe reaction, such as difficulty breathing, swelling of the face, lips, or throat, or a widespread rash with dizziness or a rapid heartbeat. While mono and its associated hives typically resolve on their own, professional medical advice ensures proper diagnosis and management.