Allergies can cause nosebleeds, medically termed epistaxis, though the connection is typically indirect. Allergies create an environment that significantly increases the likelihood of bleeding within the nasal passages. Underlying inflammation and the body’s reaction to manage symptoms combine to make the delicate nasal lining more fragile and susceptible to rupture. Understanding these mechanisms can help in both prevention and treatment.
How Allergic Inflammation Leads to Bleeding
The primary cause begins with the physiological response to allergens like pollen or dust. When the body detects an allergen, it releases inflammatory mediators, such as histamine, causing blood vessels in the nasal lining to swell and become leaky. This rich network of vessels, particularly Kiesselbach’s plexus in the anterior nasal septum, becomes engorged and fragile due to chronic inflammation. This inflammation also triggers increased mucus production, leading to congestion and a runny nose. Frequent, forceful nose blowing or rubbing then introduces physical trauma, which can rupture the swollen capillaries and cause a nosebleed.
The Secondary Role of Allergy Treatments
Paradoxically, medications used to treat allergy symptoms can also contribute to the risk of epistaxis. Common treatments, including oral antihistamines and decongestants, work by drying out nasal secretions to relieve congestion. This drying effect can dehydrate the nasal mucosa, causing the tissue to crack and become brittle, which bleeds more easily. Nasal corticosteroid sprays, while effective at reducing inflammation, can also cause localized irritation and bleeding. This is often related to improper application technique rather than the medication itself. Aiming the spray directly at the nasal septum—the central wall dividing the nostrils—can cause repeated mechanical trauma, leading to irritation and re-bleeding.
Practical Steps for Prevention and Care
Preventing allergy-related nosebleeds starts with maintaining a moist nasal environment. Using a humidifier, especially during dry seasons or when using indoor heating, helps keep the nasal passages hydrated. Applying a saline nasal spray, gel, or a thin layer of petroleum jelly inside the nostrils offers direct topical moisture.
For those using nasal sprays, correct technique is paramount to avoid trauma to the septum. When administering the spray, aim the nozzle away from the center of the nose, directing it toward the outer wall of the nostril. This technique prevents the medication from continuously irritating the vulnerable Kiesselbach’s plexus area.
If a nosebleed occurs, remain calm, sit down, and lean the head slightly forward to prevent blood from flowing down the throat. Standard care involves firmly pinching the soft part of the nose just below the bony bridge for a full 10 to 15 minutes without releasing the pressure. Avoiding strenuous activity or forceful nose blowing immediately afterward allows the fragile vessels to fully heal.