PE28.1-5 | Allergy and Asthma — Practice Quiz

Symptoms >2 days/week but not daily, with nocturnal symptoms >2×/month, classify as mild persistent asthma per GINA. The ≥12% reversibility confirms airflow obstruction that is bronchodilator-responsive.

GINA classifies childhood asthma severity by daytime frequency, nocturnal symptoms, and lung function (FEV1). Spirometric reversibility ≥12% after bronchodilator confirms asthma diagnosis.

Mild intermittent has symptoms ≤2 days/week. Moderate persistent has daily symptoms and limitation of activity. Severe persistent has continuous daytime symptoms and frequent nocturnal episodes.

For acute moderate-to-severe asthma exacerbation, nebulised salbutamol at 0.15 mg/kg (minimum 2.5 mg, maximum 5 mg) plus oral prednisolone 1–2 mg/kg is the standard initial in-hospital treatment per IAP/GINA guidance.

Acute asthma exacerbations are treated with weight-based nebulised salbutamol 0.15 mg/kg and systemic corticosteroids (prednisolone 1–2 mg/kg). MgSO₄ is added for severe/refractory cases.

MDI alone with only 2 additional puffs is insufficient for a moderate-severe exacerbation with SpO₂ 90%. IV aminophylline is a second-line agent. MgSO₄ (25 mg/kg IV, max 2 g) is indicated for severe/life-threatening exacerbations not responding to first-line therapy.

LABAs are NEVER to be used as monotherapy in asthma — including in children — because of risk of asthma-related death when used without ICS. LABAs are always added to ICS as combination therapy (Step 3+ per GINA).

LABAs are NEVER used as asthma monotherapy — they must always be combined with an inhaled corticosteroid. Violation of this rule increases risk of fatal asthma attacks.

ICS intolerance does not justify LABA monotherapy. LABAs are not first-line for mild persistent asthma — low-dose ICS is. The safety concern about LABA monotherapy applies to all age groups.

The correct pMDI + spacer technique for young children is: shake → actuate ONE puff into the spacer → child breathes 3–5 normal tidal breaths through the mouthpiece/mask. This ensures maximal aerosol deposition in the lower airways.

For children under 5–6 years, pMDI must be used with a spacer and face mask. One puff at a time is actuated into the spacer, followed by 3–5 normal tidal breaths. This maximises lower airway deposition.

Using pMDI without a spacer in young children results in poor lung deposition (drug hits the oropharynx). Rapid inhalation causes impaction of large particles in the upper airway. Actuating two puffs simultaneously is incorrect — give one puff at a time.

Bronchodilator reversibility is defined as an increase in FEV1 ≥12% from pre-bronchodilator value (some guidelines additionally require ≥200 mL absolute increase in adults). Here: (79-65)/65 × 100 = 21.5% — well above the 12% threshold, confirming reversible airflow obstruction consistent with asthma.

Bronchodilator reversibility in asthma is defined as FEV1 improvement ≥12% from pre-bronchodilator baseline after 400 mcg salbutamol. Peak flow variability (diurnal ≥20%) and exercise challenge are alternative tests.

The reversibility threshold is ≥12% increase from pre-bronchodilator FEV1, not ≥20%, and it does not require reaching >90% predicted. Spirometry with reversibility is the primary diagnostic tool for asthma; methacholine challenge is for borderline/negative spirometry with high clinical suspicion.

ARIA classification: Persistent = symptoms ≥4 days/week AND ≥4 consecutive weeks (satisfied here — daily for >4 weeks). Severity: Moderate-severe = one or more of: troublesome symptoms, sleep disturbance, impairment of daily activities/sport/leisure, or impairment at work/school. Nasal blockage every day with ocular symptoms is at minimum moderate.

ARIA classifies allergic rhinitis by frequency (intermittent <4 days/week or <4 weeks; persistent ≥4 days/week AND ≥4 weeks) and severity (mild vs moderate-severe based on impact on sleep, daily activities, and school/work).

Intermittent = <4 days/week OR <4 weeks; this patient has daily symptoms for >4 weeks, so intermittent is excluded. Mild = no troublesome symptoms and no impairment; daily nasal blockage with bilateral ocular symptoms is at least moderate severity.

INCS (e.g. fluticasone, mometasone, budesonide nasal) are the most effective therapy for allergic rhinitis. They are typically administered once daily (often morning for better adherence). Onset of action is 6–12 hours, but full clinical benefit (peak effect on nasal blockage and pruritus) requires 1–2 weeks of regular use.

Intranasal corticosteroids are first-line treatment for moderate-severe persistent allergic rhinitis in children. They require 1–2 weeks for full effect and must be used daily, not as needed.

INCS are not rescue/as-needed agents — they require consistent daily use to accumulate mucosal anti-inflammatory effect. Onset is not within 30 minutes. Twice-daily use is not required for most modern INCS. Night-only use has no evidence basis.

Salbutamol for acute asthma exacerbation in children is dosed at 0.15 mg/kg per nebulisation, minimum 2.5 mg, maximum 5 mg. For a 16 kg child: 0.15 × 16 = 2.4 mg — round up to minimum 2.5 mg. Fixed doses are incorrect; all paediatric dosing must be weight-based.

Nebulised salbutamol for paediatric acute asthma is prescribed at 0.15 mg/kg per dose (minimum 2.5 mg, maximum 5 mg), repeated every 20–30 minutes for up to 3 doses in the first hour of severe exacerbation.

A fixed 2.5 mg for all children ignores weight variation (under-doses larger children). 0.3 mg/kg is the high-dose protocol used only under close monitoring in severe refractory cases. 5 mg fixed dose may overdose small children.

Second-generation antihistamines (cetirizine, loratadine, fexofenadine) are the preferred antihistamines in children — they cause minimal sedation because they cross the blood-brain barrier poorly. They effectively relieve sneezing, rhinorrhoea, and pruritus but have limited effect on nasal congestion. Dosing is weight-based (e.g. cetirizine 0.25 mg/kg/dose). INCS remain the most effective agent for persistent allergic rhinitis.

Second-generation antihistamines are weight-dosed, preferred over first-generation in children, and address sneezing/pruritus/rhinorrhoea — but not nasal blockage. For moderate-severe persistent allergic rhinitis, INCS are the cornerstone of treatment.

Second-generation antihistamines are not fully non-sedating (cetirizine has mild sedation potential); they are ineffective against nasal blockage. First-generation antihistamines cause sedation and anticholinergic effects — not preferred. INCS, not antihistamines, are the most effective single agent for moderate-severe persistent allergic rhinitis.

Standard jet nebulisers require a driving gas flow of 6–8 L/min (oxygen or air) to generate particles in the respirable range (1–5 µm MMAD). This flow rate is sufficient for adequate aerosol output without excessive waste.

Jet nebulisers are driven by 6–8 L/min of oxygen or air. The child should breathe normally through the mask for the full nebulisation time (5–10 minutes), and the mask must fit snugly to avoid drug loss.

1–2 L/min is insufficient to drive aerosol generation efficiently (large particle size, poor lung deposition). 10–12 L/min is excessive, increases waste and may not improve deposition. 15 L/min via non-rebreather is not appropriate for nebuliser driving.