Allergic rhinitis results when allergenic materials such as dust or pollen are inhaled by a sensitised individual. The immune response involves the production of immunoglobulin E (IgE) which binds to mast cells causing the release of histamine. Histamine release results in mucus production, swelling and itching of the nasal membrane. Atopic conjunctivitis and secondary effects, as well as exacerbation of pre-existing asthma can also occur.
Based on The British Society for Allergy and Clinical Immunology (BSACI) guidelines for the diagnosis and management of allergic and non-allergic rhinitis (2017), initial treatment of allergic rhinitis would be via non-pharmacological measures such as allergen avoidance, use of barrier ointment around the nares/nasal filters and nasal saline irrigation. In pregnant patients, if these measures are insufficient, topical (intranasal/ocular) mast cell stabilisers such as sodium cromoglicate or intranasal corticosteroids should then be considered. These preparations act locally and have lower systemic absorption than oral preparations, therefore reducing fetal exposure. Where local topical therapy fails to control symptoms, oral antihistamines may be considered. Antihistamines for which human pregnancy data are available should ideally be used in preference to those for which epidemiological data are very limited or not available. The sedating effects of chlorphenamine should also be considered and the risks associated with maternal drowsiness taken into account before use in pregnancy is suggested.
Use of decongestants should be avoided due to theoretical concerns of vasoconstrictive effects affecting placental and fetal perfusion. Due to the lack of data, leukotriene receptor antagonists should also be avoided for the treatment of allergic rhinitis alone; however, they may be continued if they are already being used to treat concomitant asthma.
The available pregnancy safety data and its limitations should be discussed with the patient. Other risk factors may also be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.
This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to NHS health care professionals who are logged in.
If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.
If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.