Cockroach allergen allergy
Allergy to cockroach droppings and body parts, a common urban trigger.
About cockroach allergen allergy
Cockroach allergy is caused by proteins in the droppings, saliva, shed skins and body fragments of cockroaches, which become part of house dust and are breathed in. It is chiefly an indoor, year-round allergen and is most significant in warm, humid buildings and in densely populated urban housing where infestations take hold. When a sensitised person inhales these proteins, the immune system mounts an IgE-mediated allergic response. Internationally, cockroach allergen is a recognised and important trigger, particularly in inner-city environments; in the UK it is less prominent than dust mite but still relevant where infestations occur.
The typical presentation is persistent allergic rhinitis, with a blocked or runny nose, sneezing and itchy eyes that continue through the year rather than in a season. Cockroach allergen is strongly associated with asthma and is a well-documented contributor to poorly controlled asthma and night-time symptoms in affected households, and it may also worsen eczema. Reactions are not usually life-threatening, but ongoing asthma and disturbed sleep can have a real impact on school and work.
The cornerstone of management is reducing the infestation and exposure: keeping food sealed and surfaces clean, fixing leaks that provide water, blocking entry points and using appropriate pest control, followed by thorough cleaning to remove residual allergen. Diagnosis uses skin-prick or specific-IgE tests. Symptoms are treated with antihistamines and steroid nasal sprays, with immunotherapy considered in selected cases. See a GP if symptoms persist or asthma is hard to control.
Common triggers
- Cockroach allergen and products containing it
Symptoms
- Sneezing and a runny or blocked nose
- Itchy, red or watery eyes
- Itchy throat, nose or ears
- Coughing or wheezing
- Worsening of asthma
Avoidance & management
- Reduce exposure to the trigger where possible
- Keep windows closed during high-exposure periods
- Use air filtration and wash bedding regularly
- Shower and change clothes after exposure
- Use prescribed antihistamines, nasal sprays or preventers
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.