Hives, medically known as urticaria, are a common skin reaction characterized by itchy welts that appear on the skin. These welts can vary in size and shape, often resembling mosquito bites, and can appear anywhere on the body. While many factors can trigger hives, including allergies and physical stimuli, viral infections are a frequent and sometimes overlooked cause.
How Viruses Trigger Hives
When a virus enters the body, the immune system mounts a response. This process can lead to the release of histamine and other inflammatory chemicals from mast cells, immune cells found in the skin and other tissues.
Histamine causes small blood vessels in the skin to widen and leak fluid, leading to the characteristic raised, red, and itchy welts of hives. The immune system’s heightened state can sometimes result in an exaggerated release of these chemicals, even as it works to clear the infection.
Identifying Viral Hives
Hives caused by a viral infection appear as red or skin-colored raised welts that are itchy, and may also sting or burn. These welts often blanch, meaning they turn pale when pressed, and can change location on the body, appearing and disappearing within hours. Unlike allergic reactions that might appear immediately and fade quickly, viral hives often accompany other symptoms of a viral illness. These can include fever, fatigue, body aches, a runny nose, or a sore throat.
Viral hives may last for several days to weeks, sometimes recurring as the body fights off the infection. While individual welts typically resolve within 24 hours, new ones can continue to form, prolonging the overall rash. This pattern distinguishes them from allergic hives, which resolve once the trigger is removed.
Common Viruses Linked to Hives
Many common viral infections can lead to the development of hives. Respiratory viruses, such as those responsible for the common cold and influenza, are frequent culprits, especially in children. Hives may appear while a person is actively sick or even shortly after the infection has cleared.
Other viruses commonly associated with hives include Epstein-Barr virus, which causes mononucleosis, and various enteroviruses. Hepatitis viruses and Respiratory Syncytial Virus (RSV) have also been linked to hive outbreaks. In some cases, hives can even be the primary or only noticeable symptom of a viral infection, making the underlying cause less apparent.
Management and When to Consult a Doctor
Managing viral hives primarily involves addressing the symptoms while the body recovers from the underlying infection. Over-the-counter antihistamines are often recommended to reduce itching and swelling. Applying cool compresses to affected areas can also provide relief from discomfort. Avoid known triggers that might worsen hives, such as excessive heat or tight clothing.
While most cases of viral hives resolve on their own as the viral infection clears, certain signs warrant medical attention. Seek professional advice if hives are severe, persistent (lasting more than a few days), or accompanied by swelling of the face, lips, tongue, or throat. Difficulty breathing, wheezing, dizziness, or a racing heart along with hives are signs of a severe reaction requiring emergency care.