Men's Health

Food Allergies (Nigeria Guide)

Immune reactions to food — symptoms, trigger foods in Nigeria, and emergency management

Food allergy is an immune-mediated reaction to food proteins that causes symptoms ranging from mild hives to life-threatening anaphylaxis. It affects approximately 2–5% of adults and 6–8% of children globally. In Nigeria, the most clinically relevant food allergens differ from the Western 'Big 9' — groundnuts (peanuts), fish, shellfish, soya, egg, and milk are all significant. Food intolerance (non-immune reactions, such as lactose intolerance) is often confused with food allergy — the distinction matters for diagnosis and management.

Signs and Symptoms

✓ Skin reactions (most common) — urticaria (hives), angioedema (swelling of face, lips, tongue), eczema flare

✓ Oral allergy syndrome — itching and tingling of the mouth, lips, and throat immediately after eating

✓ Gastrointestinal — nausea, vomiting, abdominal cramps, diarrhoea within 2 hours of eating

✓ Respiratory — sneezing, runny nose, wheeze, or difficulty breathing

✓ Anaphylaxis — sudden collapse, throat closure, difficulty breathing, low blood pressure — life-threatening

✓ Delayed reactions (non-IgE mediated) — GI symptoms hours after eating (FPIES, eosinophilic oesophagitis)

Risk Factors

Family history of food allergy or atopy (eczema, asthma, hay fever)
Personal history of eczema — strong risk factor for peanut and egg allergy in children
Delayed introduction of allergenic foods in infancy — early introduction is now recommended
Sensitisation through skin rather than gut — eczema skin barrier disruption
Other established food allergies — increases likelihood of additional food allergy

When to Seek Help

Emergency — call 112 or go immediatelyThroat tightening, difficulty swallowing, voice change, wheeze, dizziness, or collapse after eating — ANAPHYLAXIS. Give adrenaline (epinephrine) if available, call for help

Same dayUrticaria (hives) spreading rapidly over large body areas, swelling of lips or tongue

SoonSuspected food allergy — diagnostic testing needed before dietary elimination

RoutineRecurrent unexplained urticaria or GI symptoms — food allergy or other cause investigation

Paediatric allergy referralChild with eczema and suspected food allergy — early assessment and introduction guidance

Tests & Diagnosis

🧪 Skin prick test

With commercial or fresh food extracts — positive wheal (≥3 mm greater than negative control) supports IgE-mediated allergy. Available at allergy clinics

🧪 Serum specific IgE (food panels)

Blood test — measures IgE to specific foods (peanut, milk, egg, fish, soya, wheat panels). A positive result means sensitisation — not always clinical allergy

🧪 Oral food challenge (OFC)

Gold standard for diagnosis — supervised ingestion of increasing amounts of the suspected food. Performed in a clinical setting with emergency resuscitation available. Confirms or excludes clinical allergy

🧪 Elimination diet trial

Remove suspected food for 4–6 weeks, then reintroduce under medical supervision — used for suspected non-IgE-mediated allergy where skin testing is negative

🧪 Atopy patch test

For delayed GI and skin reactions (FPIES, eosinophilic conditions) — not routine

Treatment Options

Strict avoidance of the identified allergen

Read ingredient labels carefully. Nigerian processed foods increasingly include allergen labelling. Beware of cross-contamination in food preparation. Inform restaurants and food vendors of your allergy

Emergency adrenaline (epinephrine) auto-injector

All patients with a history of anaphylaxis must carry an adrenaline auto-injector (Epipen or equivalent). Available at major Nigerian pharmacies and LUTH/UCH immunology clinics. Two pens should be carried at all times. Train the patient and family to use it

Antihistamines for mild reactions

Cetirizine or loratadine for mild urticaria. Chlorphenamine for more rapid effect (sedating). Antihistamines are NOT effective for anaphylaxis — adrenaline is the only life-saving treatment

Oral allergy syndrome

Usually managed by avoiding the raw food — cooking destroys the proteins causing oral allergy. Most people with oral allergy syndrome can tolerate cooked versions of the triggering food

Lactose intolerance vs milk allergy

Lactose intolerance (very common in Nigeria — most adult Nigerians lack lactase) causes bloating, gas, and diarrhoea — but no hives, swelling, or anaphylaxis. Treatment: lactase enzyme supplements or low-lactose products. Milk protein allergy (IgE-mediated) causes immune reactions — strict avoidance needed

Food allergy in children — early introduction

Contrary to old advice, early introduction of allergenic foods (from 4–6 months) PREVENTS allergy development. Children with eczema should have early introduction under medical guidance. LEAP study evidence: early peanut introduction reduces peanut allergy by 80%

Immunotherapy for food allergy (oral immunotherapy — OIT)

Gradually increasing doses of the allergen to induce tolerance. Primarily for peanut (approved: Palforzia). Not yet widely available in Nigeria. Can be life-changing for children with severe peanut allergy

Frequently Asked Questions

Is groundnut (peanut) allergy common in Nigeria?

Yes — though rates are lower than in Western countries (possibly due to early introduction in Nigerian diets from infancy). Peanut allergy is the most common cause of fatal anaphylaxis in children worldwide. Nigerian children who have not been regularly eating groundnuts should not be given them for the first time without medical guidance if they have eczema or other allergies.

Can you develop a food allergy as an adult?

Yes. New food allergies can develop at any age. Shellfish allergy commonly develops in adults who have eaten shellfish for years. Wheat allergy can develop in bakers (occupational allergy). Any new unexplained reaction after eating a food warrants allergy evaluation.

Is food intolerance the same as food allergy?

No. Food allergy involves the immune system — even tiny amounts can cause severe reactions including anaphylaxis. Food intolerance (e.g., lactose intolerance, histamine intolerance) causes discomfort but is not immune-mediated and is not life-threatening. The distinction matters for severity of avoidance and need for adrenaline.

What should I do if I accidentally eat a food I'm allergic to?

Mild symptoms (hives, itching): take an antihistamine and observe closely. Throat tightening, difficulty breathing, voice change, dizziness, or feeling faint: use adrenaline auto-injector immediately if available, then call for emergency help. Always go to hospital after using adrenaline — biphasic reactions (second wave of anaphylaxis) can occur up to 8 hours later.