Optimal Management of Allergic Rhinitis in Children and Non-Allergic Rhinitis in Children

Overview and Definition of Allergic Rhinitis (AR)

• General Context: Allergic rhinitis (AR) is recognized as the most common chronic disease in childhood, though it is frequently ignored, misdiagnosed, or mistreated.
• Definition: Rhinitis is clinically defined as the presence of at least two nasal symptoms, including:
  • Rhinorrhoea (nasal discharge).
  • Nasal blockage (obstruction).
  • Sneezing.
  • Itching.
• Pathophysiology: AR is an inflammatory condition of the nasal mucosa driven by immunoglobulin E (IgE)-mediated early-phase and late-phase hypersensitivity responses. These responses are typically triggered by inhalant allergens, mirroring the mechanisms found in allergic asthma.
• Common Allergens: Typical triggers include:
  • House dust mite (HDM).
  • Grass and tree pollens.
  • Animal dander (cats, dogs, horses).
  • Moulds (occasionally).
• Phenotypes:
  • "Sneezers and runners": Easily recognized by obvious sneezing and rhinorrhoea.
  • "Blockers": Predominant nasal obstruction, which is more likely to be misdiagnosed.

Systemic Impact and Comorbidities

• Quality of Life (QoL): Undertreated AR impacts physical, social, and psychological well-being. It is linked to poor sleep quality, fatigue, and impaired concentration.
• Educational Impact: Uncontrolled symptoms and the use of sedating antihistamines reduce school performance, including measurable impacts at the General Certificate of Secondary Education (GCSE) level.
• Connection to Asthma:
  • Over $75\%$ of children with asthma also suffer from AR.
  • AR is a major factor in asthma development and often precedes it in preadolescence or adolescence.
  • AR carries a $3\text{-fold}$ risk of asthma persisting into middle age.
  • Moderate to severe rhinitis correlates with poor asthma control.
  • Physiological indicators in AR children include bronchial hyper-responsiveness, raised exhaled nitric oxide, and reduced lung function.
• Other Inflammatory Conditions: AR is part of a systemic process often associated with:
  • Allergic Conjunctivitis (AC): Occurs in $50\% \text{--} 70\%$ of AR patients; it is a key differentiator between AR and other rhinitis forms.
  • Rhinosinusitis: Minimal persistent inflammation synergizes with infective inflammation, leading to more viral colds.
  • Otitis Media with Effusion: Linked to Eustachian tube dysfunction.
  • Adenoidal Hypertrophy: May be associated with AR; some children show improvement in sleep or hypoxia following AR treatment.
  • Oral Allergy Syndrome (OAS): Also known as pollen fruit syndrome. Cross-reactivity between pollen and molecules in fresh fruits/vegetables (e.g., apples, hazelnuts, carrots, celery, peanuts) causes oral pruritus or angioedema.

Classification and Clinical Diagnosis

• Allergic Rhinitis and its Impact on Asthma (ARIA) Classification:
  • Mild Intermittent: Symptoms occurring $< 4\text{ days/week}$ OR for $< 4\text{ weeks}$.
  • Moderate/Severe Intermittent: Symptoms with impact on sleep or daily activities.
  • Mild Persistent: Symptoms occurring $\ge 4\text{ days/week}$ AND for $\ge 4\text{ weeks}$.
  • Moderate/Severe Persistent: Persistent symptoms with significant QoL impairment (validated in an epidemiological survey of $1275$ children aged $6\text{--} 12$ years).
• Physical Examination Findings:
  • Allergic Salute: Rubbing the nose upwards, causing a crease across the nasal bridge.
  • Denny–Morgan Lines: Extra skin folds or lines under the lower eyelids.
  • Allergic Shiners: Dark shadows beneath the lower lids caused by fluid accumulation in the infraorbital groove; darker in severe chronic cases.
  • Internal Examination: Essential to use an otoscope or endoscope to rule out nasal polyps.
• Differential Diagnoses:
  • Chronic unremitting rhinitis from birth: Suggests primary ciliary dyskinesia.
  • Unilateral blockage with purulent discharge: Suggests a foreign body or unilateral choanal atresia.
  • Watery discharge on bending forward: Suggests a cerebrospinal fluid (CSF) leak.
  • Nasal polyps: Should lead to testing for cystic fibrosis.
  • Adolescents: Oral contraceptives can cause hormonal rhinitis.

Diagnostic Investigations

• Skin-Prick Testing (SPT): The preferred method, providing results within $15\text{ min}$. It is often more cost-effective than blood tests.
• Serum-Specific IgE: Blood tests used when SPT is not feasible, such as in patients with:
  • Dermatographism.
  • Severe atopic dermatitis.
  • Inability to stop antihistamines.
• Interpretation Warning: An isolated positive IgE test without symptoms indicates "sensitization" rather than clinical disease. Broad "fishing expeditions" with multiple tests are not recommended.
• Other Tests: Measurements of nasal patency and lung function tests are helpful, especially if chest symptoms are present.

Pharmacotherapy and Management Hierarchy

• Allergen Avoidance: The first step. Includes nasal air filters for pollens and pet avoidance. House dust mite reduction measures show equivocal benefits in isolation.
• Saline Douching: Inexpensive, well-tolerated, and reduces symptoms while improving the efficacy of intranasal steroids (INS).
• Antihistamines:
  • Non-sedating: Recommended for mild to moderate disease.
  • Intranasal vs. Oral: Intranasal antihistamines have a faster onset ($15\text{ min}$ vs. $1\text{ h}$) and are more effective on nasal symptoms but may be less tolerated than oral forms.
  • First-generation: Sedating antihistamines cause psychomotor retardation and should no longer be used.
• Intranasal Corticosteroids (INS):
  • The most effective treatment for nasal symptoms, especially nasal obstruction.
  • Superior to antihistamines and leukotriene receptor antagonists (LTRAs).
  • Molecules: Mometasone furoate and fluticasone propionate have extremely low systemic bioavailability.
  • Growth Safety: Studies for over $1\text{ year}$ showed no adverse effects on cortisol levels or growth with mometasone or fluticasone propionate. However, a double dose of fluticasone furoate ($110\,\mu g/day$) was associated with growth reduction.
  • Administration: Should be used regularly in the morning. Use the lowest dose to maintain control. "Holidays" from treatment are ineffective for reducing systemic effects and cause loss of control.
• Leukotriene Receptor Antagonists (LTRA): Effects similar to oral antihistamines. Suggested by ARIA 2010 for seasonal AR, preschool children, or those with concomitant asthma where steroid concerns exist.
• Rescue Therapy: Short courses of low-dose oral prednisolone or decongestants may be used for very severe symptoms. Depot corticosteroid injections are NOT recommended due to risks like avascular necrosis of the hips.

Allergen-Specific Immunotherapy (SIT)

• Mechanism: The only treatment uniquely able to alter long-term disease outcomes (disease-modifying effect).
• Forms:
  • Subcutaneous Immunotherapy (SCIT): Currently $75\%$ of SIT in Europe. Requires administration by competent practitioners due to small risk of anaphylaxis (requires adrenaline availability).
  • Sublingual Immunotherapy (SLIT): Currently $25\%$ of SIT in Europe. High safety profile and proven efficacy for grass pollen allergy (hay fever). HDM results are variable.
• Prevention of Asthma Study (PAT): Demonstrated that $3\text{ years}$ of SCIT for hay fever reduced new asthma cases at $3$, $5$, and $10\text{ year}$ follow-ups compared to pharmacotherapy alone.
• Indications: Recommended for severe AR uncontrolled by standard pharmacotherapy.

Administration Technique and Education

• Nasal Spray Technique: The spray should be directed toward the lateral wall of the nose, avoiding the septum. This allows mucociliary clearance to distribute the medication.
• Nasal Drops: Superior for rhinosinusitis; should be administered with the head completely upside down to reach the ostiomeatal complex.
• Patient Education: Practitioners must explain the delay in action for INS, the necessity of regular use, and potential side effects to improve concordance and prevent switching to older, more bioavailable molecules based on misinformation.