Allergies and Asthma in Malaysia: Triggers, Testing & Treatment

Allergic rhinitis (AR) — commonly called "nasal allergy" or "sinus allergy" — affects an estimated 20 to 30% of Malaysians and is the most prevalent allergic condition. Despite being treatable, it causes significant quality of life impairment, lost school and work productivity, and when poorly controlled, contributes substantially to asthma. Symptoms: watery nasal discharge, sneezing (often in bouts, especially in the morning), nasal congestion, and itchy nose, eyes, and palate. Dark circles under the eyes ("allergic shiners") and the "allergic salute" (rubbing the nose upward) are signs in children. Types: - Perennial AR: year-round symptoms, typically due to indoor allergens (dust mites, cockroach, mould). Very common in Malaysia due to year-round allergen exposure. - Seasonal AR: symptoms linked to pollen seasons — less marked in equatorial Malaysia than in temperate regions but still present. Treatment: - Intranasal corticosteroid sprays (fluticasone, budesonide, mometasone): the most effective treatment for AR. Must be used daily for at least 2 weeks to see full effect. Very low systemic absorption — safe for long-term use. - Non-sedating antihistamines (cetirizine, loratadine, fexofenadine): useful for sneezing and itch but less effective for nasal congestion than intranasal steroids. - Environmental control: dust mite-proof covers for mattresses and pillows, washing bedding at 60 degrees C weekly, HEPA air purifiers, and keeping humidity below 50%. The rhinitis-asthma link: up to 80% of asthmatic patients also have allergic rhinitis. Treating rhinitis improves asthma control.

Drug allergies are an important area where accurate diagnosis matters enormously. Many Malaysians carry labels of "penicillin allergy" or "antibiotic allergy" that are based on non-allergic reactions or have been outgrown, unnecessarily restricting their antibiotic choices. True drug allergy is immune-mediated. The most important reactions: - Anaphylaxis: severe, immediate (within 1 hour) — urticaria, angioedema, hypotension, bronchospasm. Requires adrenaline and emergency care. - Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis (SJS/TEN): rare, severe blistering skin reaction. A medical emergency. Common drug allergy concerns in Malaysian patients: - Penicillin/Amoxicillin allergy: studies show up to 80 to 90% of patients labelled as "penicillin allergic" can actually tolerate penicillin safely on formal testing. Penicillin allergy de-labelling (re-testing to confirm or refute the allergy) is clinically important. - Aspirin and NSAID hypersensitivity: may cause urticaria, worsening of asthma, or respiratory reactions. Separate mechanism from IgE allergy but clinically important. - Allopurinol allergy: carries a very small risk of severe SJS/TEN, particularly in those with the HLA-B*5801 allele (more common in Han Chinese, Thai, and Korean populations). Genetic testing before starting allopurinol is recommended in these groups. Report any drug reaction to your doctor. Record: the drug name, dose, timing of reaction, and exact symptoms. This history helps your doctor assess whether it was a true allergy or an expected side effect.