Symptoms & Clinical Features

• Recurrent episodes of wheezing, breathlessness, chest tightness, and cough (often worse at night/early morning). Symptoms are usually of variable intensity and intermittent.
• Symptoms vary seasonally or with triggers (exercise, allergens, infections)
• Features of allergy may be present especially in those with allergy-predominant asthma.
• Nigerian specific: High rates of aspirin-exacerbated respiratory disease reported; frequent exacerbations during harmattan (dry, dusty season) (Adeyeye et al., 2021; African Journal of Respiratory Medicine)
• Clinical signs: Expiratory wheezing, increased respiratory rate, prolonged expiratory phase, use of accessory muscles during exacerbations. Depending on the degree of exacerbation, the patient may be cyanosed with low oxygen saturation, diaphoretic, with silent chest in case of life-threatening attack. 

Differential Diagnosis

• COPD (particularly asthma-COPD overlap)
• Vocal cord dysfunction: wheeze is at the level of the vocal cord and not responsive to inhalers and known asthma therapies. May co-exist with asthma.
• Gastroesophageal reflux disease: presenting as “difficult to treat asthma”, particular with disturbing dry cough, sensation of acid brash in the mouth. Presenting mostly during sleep and commoner in obese individuals
• Bronchiectasis: recurrent chest infection leading to irreversible airway damage and dilation. 
• Heart failure (cardiac asthma): acute left ventricular heart failure presenting with cough of frothy-pinkish sputum with wheeze
• Foreign body aspiration (especially in children): particular causing large airway obstruction.

Investigations

1. Spirometry: Reversible airflow obstruction (≥12% and 200mL increase in FEV₁ post-bronchodilator)
2. Peak Expiratory Flow: Variability >20% between measurements
3. FeNO: Elevated fractional exhaled nitric oxide (>50 ppb suggests eosinophilic inflammation)
4. Allergy testing: Skin prick tests or specific IgE
5. Chest X-ray: Typically, normal but rules out other pathology especially pneumothorax, heart failure and chest infections among others
   African context: Limited access to spirometry in primary care; reliance on clinical diagnosis common (Binegdie et al., 2015; Pan African Medical Journal)

Treatment

Stepwise approach (GINA 2024 guidelines):

• Step 1: As-needed low-dose ICS-formoterol for mild asthma
• Step 2-5: Regular maintenance therapy with ICS-LABA combinations
• Acute exacerbations: Systemic corticosteroids, oxygen, nebulized SABA
• Nigerian adaptation: Challenges with inhaler affordability; increasing use of locally produced MDI spacers from plastic bottles (Desalu et al., 2019; Nigerian Journal of Clinical Practice)

Follow-up

• Every 3-6 months for stable patients, monthly for poorly controlled disease.
• Assess symptom control (ACT questionnaire), asthma action plan, inhaler technique, adherence
• Review environmental trigger avoidance

Prevention & Control

• Identification and avoidance of triggers (dust mites, cockroaches in humid climates)
• Education on inhaler technique (demonstrate-return-demonstrate method)
• Influenza and pneumococcal vaccination
• Community programs: "Asthma Friendly Schools" initiatives in Lagos showing promise (Fadare & Ojo, 2020)

Conclusion and Experience from the clinic

Asthma management in Nigeria requires culturally adapted education, improved access to diagnostics, and affordable inhaled medications. Integration of asthma care into primary health systems is crucial for reducing morbidity. 

Majority of the patients with asthma are diagnosed clinically, some correctly while others were wrongly pronounced. In most cases, the initial points of contact either place the patients on SABA only, or with oral steroids and some antihistamines. Such patients usually present with uncontrolled disease with profound side-effects of the wrong regimen. When not sure or in doubt, always refer your patient to a specialist for proper evaluation including spirometry, guidance on appropriate inhalers and techniques, so as use of asthma action plan.