Mouse allergy
Allergy to mouse proteins, common in labs and homes.
About mouse allergy
Mouse allergy is an IgE-mediated reaction to proteins carried mainly in mouse urine, and also in dander (skin flakes) and saliva, rather than the fur. The major mouse allergen, Mus m 1, is a urinary protein, so contamination of bedding, cage litter and surfaces is an important source of exposure. It affects people who keep mice as pets, but is a well-recognised occupational allergy among laboratory workers, and mice living unseen in buildings can also raise indoor allergen levels. The particles are light, become airborne easily and settle widely, lingering on clothing and in homes and workplaces.
Symptoms typically appear within minutes to hours of contact and include sneezing, a runny or blocked nose and itchy, watering eyes. In susceptible people, handling mice or disturbing contaminated bedding can trigger asthma symptoms or aggravate eczema. Because the allergen is airborne and spreads onto surfaces, reactions can occur without touching an animal, simply from being in an infested or poorly cleaned space. These reactions are generally uncomfortable rather than dangerous.
Diagnosis is made with a skin-prick or specific-IgE blood test alongside your history and, where relevant, your occupation. Removing pet mice, or eliminating an infestation, is most effective; where mice must be handled, reduction measures help, including good ventilation, dust control, gloves and a mask, changing out of work clothes and washing hands. Medicines relieve symptoms, and immunotherapy is considered in selected cases. See your GP, especially if breathing symptoms develop.
Common triggers
- Mouse and products containing it
Symptoms
- Sneezing and a runny or blocked nose
- Itchy, watery eyes
- Skin redness where the animal licked or touched
- Coughing or wheezing
- Worsening of asthma
Avoidance & management
- Limit contact with the animal
- Keep pets out of bedrooms
- Wash hands and clothes after contact
- Use air filtration and vacuum often
- Take prescribed antihistamines
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.