Yes, allergies can make you sweat, though the mechanism is indirect and often misunderstood. The sweating is typically not a direct symptom of the allergy itself, but rather a consequence of the body’s systemic response to the allergic reaction or a side effect of the medications used to treat the symptoms. Common environmental or seasonal allergies, such as those caused by pollen or dust mites, trigger a chain reaction within the body that can affect temperature regulation.
The Inflammatory Link Between Allergies and Sweating
An allergic reaction is an inflammatory event where the immune system releases chemical mediators in response to a perceived threat. Mast cells release histamine, which is primarily known for causing sneezing and itching, but also acts on the circulatory system. Histamine causes vasodilation—a widening of the blood vessels—which increases blood flow to the skin’s surface.
This increased blood flow acts as internal warming, which the body must counteract to maintain its core temperature. The brain’s thermoregulatory center interprets this systemic change as a need to cool down, triggering the sweating reflex, or diaphoresis. Sweating, in this context, is the body’s attempt to restore thermal balance disrupted by the widespread inflammatory response.
The physical strain of severe allergy symptoms can also induce secondary sweating. Persistent, forceful coughing fits or intense nasal congestion that causes labored breathing increase physical exertion. This heightened effort stimulates the sympathetic nervous system, releasing hormones like adrenaline that naturally increase heart rate and metabolism, leading to a rise in body temperature and subsequent perspiration.
How Allergy Medications Affect Body Temperature
Increased sweating is often a side effect of medications taken to control allergy symptoms. Many decongestants, particularly those containing pseudoephedrine, act as sympathomimetic agents that stimulate the nervous system, mimicking the effects of adrenaline. While they constrict blood vessels in the nasal passages to reduce swelling, this action also increases the heart rate and raises the body’s overall metabolic rate.
This systemic stimulation generates internal heat, and the body reacts by initiating a sweating response to prevent overheating. This is a known, though less common, side effect of stimulant medications.
Oral corticosteroids, sometimes prescribed for severe allergic inflammation or chronic conditions, can also influence body temperature regulation. These anti-inflammatory drugs impact the endocrine system, leading to hormonal fluctuations. This disruption can manifest as symptoms like hot flashes and night sweats, which are forms of sudden perspiration unrelated to the initial allergic trigger.
When Sweating Indicates Something More Than Allergies
While sweating can be a benign side effect of an allergy response, it must be distinguished from signs of an infection. Allergies do not cause a fever, defined as an elevated core body temperature typically above 100.4°F (38°C). If excessive sweating is accompanied by fever, chills, or body aches, the cause is likely a bacterial or viral infection, not the allergy itself.
Another distinguishing factor is the nature of nasal discharge. Allergy-related mucus is usually clear, thin, and watery due to the rapid release of inflammatory chemicals. Conversely, an infection, such as sinusitis, is often characterized by thick, yellowish or green mucus. If the sweating is sudden, severe, and accompanied by shortness of breath or chest pain, it may signal a serious medical issue requiring immediate attention.
Practical Steps for Relief
Managing allergy-related sweating involves controlling the underlying allergy and addressing the perspiration directly. Effective management through antihistamines or nasal sprays reduces internal inflammation and the subsequent need for thermal regulation. Reducing the severity of congestion and coughing also lessens the physical exertion that contributes to sweating.
To manage the discomfort, focus on environmental control by keeping the sleeping area cool and well-ventilated. Wearing lightweight, breathable fabrics helps sweat evaporate from the skin, and adequate hydration helps the body maintain temperature balance. Antiperspirants, which temporarily plug sweat ducts, can be applied to affected areas, often working best when applied at night. If a decongestant is suspected of causing the sweating, discuss alternative, non-stimulant allergy medications with a healthcare provider.