Paediatric Allergic Rhinitis

Allergy Ireland's Dr Colm Cosgrove features in the Irish Medical Times in July 2021

Irish Medical Times: Paediatric Allergic Rhinitis

Allergic Rhinitis (AR) is a common condition characterised by nasal congestion, nasal itching, sneezing and rhinorrhoea, and is caused by IgE-mediated reactions to inhaled allergens such as dust mites, pollens and animal dander. AR is thought to be the consequence of environmental exposure on a background of genetic predisposition, and is often associated with other conditions such as asthma, conjunctivitis and eczema.(1)

The prevalence of AR is difficult to accurately measure, but is thought to be up to 50% in some countries.(2) The UK has a prevalence of 26% and Ireland is likely to be similar to this. AR in childhood is common, and likely under-diagnosed, as many children will have difficulty reporting symptoms, or indeed will know no different and assume their rhinitis symptoms are normal.(3) It is clear that the prevalence of AR is increasing globally. The ISAAC study (2006) demonstrated an increase in prevalence among 13-14yr olds from 13% to 19% over an 8-year period.(4)

Whilst by definition, AR describes a disorder of the nasal cavity, it has more recently come to be thought of as part of a ‘united airways disease’, involving both the upper and lower respiratory tract. Exposure to an allergen provokes local inflammation in the lining of the nose, and may also trigger an inflammatory response in the lower airways, presenting as asthma. AR and asthma commonly co-exist, and AR is known to be a risk factor for developing asthma – patients with AR have a threefold greater risk of developing asthma. Also, improving rhinitis symptoms over time correlates with an improvement in asthma symptoms.(5)

The ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines classify AR based on duration of symptoms (intermittent vs persistent) and severity of symptoms (depending on how overall quality of life is affected).(6)

Presentation
The main symptoms of AR include rhinorrhoea, nasal congestion, postnasal drip, sneezing, snoring, irritant cough and sometimes headaches. Presentation is quite rare in children under the age of two, and symptoms are often difficult to appreciate in this age group, with most parents putting them down to recurrent colds.

The severity of symptoms in older children is often under-appreciated, as the child may have accommodated to the symptoms over several years, to the extent that they are unaware that there is a problem at all.

AR in childhood can have a major impact on the overall quality of life of the child. The degree to which a child is affected by AR depends on a number of factors, including age, the specific allergen to which the child reacts, and the environment or activities in which the child is involved. For example, a child with a pollen allergy may have difficulty taking part in outdoor sports or games with peers, which can lead to effects on physical fitness and social interactions.

Children with allergies often feel left out or left behind in sporting areas. Similarly, a child with a passion for animals, but who suffers from an allergy to certain animal dander, may be deeply emotionally affected by not being able to become involved with animals or pets as much as they would wish to. Children suffering from AR can often present with problems in school or learning difficulties. This can be due to several mechanisms. Poor symptom control during the day can lead to distraction and poor concentration in the classroom. Poor symptom control at night leads to sleep disturbance and subsequent daytime fatigue.

Occasionally, side-effects of medications used to treat AR (usually first-generation anti-histamines causing drowsiness, and thankfully not frequently used nowadays) can adversely affect school performance. Furthermore, it has been shown that ADHD is more common in children with AR.(7) Sleep is a huge issue for children with AR. It has been proven that AR is associated with snoring and obstructive sleep apnoea.(8) This in turn leads to daytime somnolence and further effects on physical and mental wellbeing as a result.

There are certain physical characteristics which can often be identified in children with AR, which can give clues to the diagnosis. Dark circles under the eyes and puffiness of the lower eyelids (‘allergic shiners’) can be related to vasodilation and nasal congestion; while a nasal crease across the lower half of the bridge of the nose can be caused by repetitive upwards rubbing of the nose by the palm of the hand (the ‘allergic salute’). There may also be malocclusion of the jaw and discolouration of the frontal incisors as a result of chronic mouth-breathing secondary to nasal congestion. Examination of the nose in a child with AR usually reveals enlarged oedematous turbinates, pale mucosa and excess mucus. The eyes may show signs of conjunctivitis, and the ears may reveal a middle ear effusion or chronic infection.

Investigation

Skin-prick testing is a quick and non-invasive method of determining specific inhalant allergens in children from six months onwards. The most common inhalant allergens identified are dust mite, grass pollen, tree pollen, moulds and animal dander.

Management
Initial management for all age groups involves minimising exposure to the identified allergen, and if possible avoidance altogether.

Measures to reduce dust mite exposure include avoiding carpet, particularly in the bedroom, avoiding feather pillows/duvets (ideally using hypo-allergenic bedding), hoovering regularly, and trying to reduce the number of teddies in the bed!

Avoiding pollen is difficult, but it is important to keep an eye on the pollen count, to change clothes when returning from outdoors and try to avoid drying clothes on an outside line (as clothes will gather pollen during the day). Keeping windows closed at home and while in the car can reduce exposure, and wrap-around sunglasses can help with eye involvement. Allergy avoidance alone is usually not sufficient to completely manage the symptoms. Further treatment options depend on the age of the child:

Age 0-2
Treatment is quite limited in this age group. Saline nasal sprays can be helpful to ease congestion, and if symptoms are particularly troublesome, low-dose second generation anti-histamines (eg: Cetirizine liquid) may be considered.

Age 3-5
In addition to the above measures, intranasal corticosteroids are considered first-line treatment for moderate-severe AR, as included in the latest ARIA guidelines,(6) and can be used from age three onwards. These sprays can be used regularly.

Sometimes it is necessary to use corticosteroid drops initially, before using the spray, to help reduce oedema in the nasal cavity. Again, anti-histamines may be used for symptom flare-ups.

Leukotriene-receptor antagonists (LTRAs) such as Montelukast can also be added, and can be particularly effective when there are symptoms of lower airway irritability.

Age six and over
While the above treatments will continue to be useful, there are some further options for those over six. Immunotherapy is a very effective way of improving symptoms and reducing reactions to specific allergens. It is also now included in the ARIA guidelines.(6)

Essentially, immunotherapy involves exposing the individual to tiny amounts of a specific allergen in a controlled way, over a prolonged period of time, allowing the body to mount a response which enables the child to build a resistance to the allergen.(9)

In Ireland, immunotherapy is usually given as a sublingual medication over several years, and is currently available for grass pollen from age six. It is expected that dust mite and tree pollen immunotherapy will be licensed for children in the near future.

Phototherapy can also be used in the nasal cavity to reduce symptoms of AR. This involves treating the lining of the nose with a combination of UV-A, UV-B and visible light, which inhibits allergen-induced histamine release from mast cells and induces apoptosis of eosinophils and T-lymphocytes. This local immunosuppressive effect can significantly reduce the degree to which a child reacts to inhaled allergens.

References

1. Bousquet J, Anto JM, Baggert C, et al., Allergic Rhinitis, Nature Reviews Disease Primers 2020; Volume 6, Article number: 95.
2. Bousquet, P. J. et al. Geographical distribution of atopic rhinitis in the European community respiratory health survey I. Allergy 63, 1301–1309 (2008).
3. Bauchau V, Durham SR. Prevalence and rate of diagnosis of allergic rhinitis in Europe. European Respiratory Journal 2004; 24(5): 758.
4. Asher MI, Montefort S, Bjorksten B, et al. Worldwide time trends in the prevalence of symptoms of asthma, allergic rhino conjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multi-country cross-sectional surveys. Lancet 2006; 368(9537): 733-43.
5. Adams RJ, Fuhlbrigge AL, Finkelstein JA. Weiss ST Intranasalsteroids and the risk of emergency department visits for asthma. J Allergy Clin Immunol 2002;109:636–42.
6. Bousquet J, Schunemann HJ, Togias A, et al. Next-generation Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines for allergic rhinitis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE) and real-world evidence. J Allergy Clin Immunol 2020; 145(1): 70-80.e3.
7. Brawley A, Silverman B, Kearney S, et al. Allergic rhinitis inchildren with attention-deficit/hyperactivity disorder. Ann Allergy Asthma Immunol 2004;92:663–7.
8. Canova CR, Downs SH, Knoblauch A, Andersson M, Tamm M, Leuppi JD. Increased prevalence of perennial allergic rhinitis inpatients with obstructive sleep apnea. Respiration 2004;71:138–43.
9. Zielen S Devillier P Heinrich J Richter H Wahn U Sublingual immunotherapy provides long-term relief in allergic rhinitis and reduces the risk of asthma: A retrospective, real-world database analysis. Allergy. 2018; 73: 165–177.