First line allergy medication forms the cornerstone of managing common allergic conditions in the UK, from hay fever and urticaria to allergic conjunctivitis and eczema. These are the treatments — including non-sedating antihistamines, intranasal corticosteroids, and topical therapies — that pharmacists and GPs recommend before considering specialist interventions. Many are available over the counter at UK pharmacies, making them accessible for prompt symptom relief. Understanding which medication is appropriate, how each works, and when to seek further advice is essential for safe and effective allergy management. This guide covers NHS and NICE-aligned recommendations to help patients and carers make informed decisions.

What Is First Line Allergy Medication?

First line allergy medication refers to the initial treatments recommended when a person presents with allergic symptoms. These are the therapies that clinicians and pharmacists suggest before considering more specialist or second-line interventions. In the UK, many first line allergy medications are available over the counter at pharmacies, though age restrictions and pharmacy supervision requirements apply to some products — for example, most intranasal corticosteroid sprays are classified as Pharmacy (P) medicines for adults aged 18 and over, and children generally require clinical advice before use.

Allergic conditions are among the most common reasons people seek medical advice in primary care. They encompass a wide range of presentations, including allergic rhinitis (hay fever), urticaria (hives), allergic conjunctivitis, and atopic dermatitis (eczema), which can be triggered or worsened by allergens. The choice of first line treatment depends on the type and severity of the allergic response, the patient's age, and any co-existing medical conditions.

New or recurrent symptoms that may be related to food should prompt GP or allergy advice and avoidance of the suspected trigger until properly assessed, rather than self-management alone.

The overarching goal of first line allergy medication is to relieve symptoms promptly, reduce inflammation, and improve quality of life. These treatments do not cure the underlying allergy but manage the immune system's exaggerated response to a trigger — known as an allergen. When symptoms are mild to moderate and well-controlled with first line options, referral to a specialist allergy service is generally not required. However, if symptoms persist or worsen, further assessment is warranted.

Patients who are pregnant or breastfeeding should consult a pharmacist or GP before starting any allergy medication, as not all products are suitable during pregnancy or lactation.

Types of Allergy Medication Recommended in the UK

In the UK, several categories of medication are considered first line for managing allergic conditions. The most widely used are oral antihistamines, which are available in both sedating and non-sedating formulations. Non-sedating (second-generation) antihistamines such as cetirizine, loratadine, and fexofenadine are generally preferred due to their favourable side-effect profile and once-daily dosing.

Regarding fexofenadine, it is important to note that the 120 mg strength (licensed for hay fever, usually from age 12) is available as a Pharmacy (P) medicine. The 180 mg strength (used, for example, in chronic urticaria) remains a prescription-only medicine (POM) — patients should follow pharmacist or GP advice on which strength is appropriate.

For allergic rhinitis, intranasal corticosteroid sprays — such as beclometasone or fluticasone propionate — are considered highly effective and are recommended as first line treatment by NICE, particularly when nasal congestion is a prominent symptom. These sprays work locally within the nasal passages and have minimal systemic absorption when used correctly. They are available over the counter in the UK for adults aged 18 and over.

Other first line options include:

• Sodium cromoglicate eye drops — usually considered first line for allergic conjunctivitis; azelastine eye drops may be used if symptoms persist or as an alternative

• Emollients as the foundation of atopic dermatitis management, with mild topical corticosteroids used for short courses during flares; use the lowest effective potency, avoid the face and skin folds unless specifically advised, observe product age limits, and seek advice if skin infection is suspected

• Antihistamine syrups or tablets for children, with age-appropriate dosing as specified on the product label

• Sodium cromoglicate nasal spray as an alternative for those who cannot tolerate intranasal corticosteroids

For acute allergic reactions that are mild, an oral antihistamine is typically the first step. It is important to note that adrenaline auto-injectors (e.g., EpiPen) are reserved for anaphylaxis and are not considered routine first line allergy medication for mild presentations.

Decongestants (oral or intranasal) are not considered first line allergy treatments. Intranasal decongestants should be limited to a maximum of seven days to avoid rebound nasal congestion (rhinitis medicamentosa).

How Antihistamines and Other Treatments Work

Understanding the mechanism of action of first line allergy medication helps patients use these treatments more effectively. When the body encounters an allergen, the immune system triggers the release of histamine from mast cells and basophils. Histamine binds to H1 receptors throughout the body, causing the familiar symptoms of allergy: itching, sneezing, watery eyes, nasal congestion, and skin reactions.

Antihistamines work by competitively blocking H1 receptors, thereby preventing histamine from exerting its effects. Second-generation antihistamines such as cetirizine and loratadine are selective for peripheral H1 receptors and have limited ability to cross the blood-brain barrier, which is why they cause significantly less sedation than older, first-generation antihistamines like chlorphenamine. It is worth noting that oral antihistamines have limited effect on nasal congestion compared with intranasal corticosteroids, which are more effective for this symptom.

Intranasal corticosteroids act via glucocorticoid receptor-mediated gene transcription, reducing inflammatory cell infiltration and the production of multiple inflammatory mediators — including histamine, prostaglandins, and leukotrienes — and decreasing mucosal oedema. Their onset of action may take several days to two weeks, so patients should be advised to begin treatment before the allergy season starts for optimal effect. Regular daily use, rather than as-needed dosing, provides the best results.

Topical corticosteroids used in atopic dermatitis management work similarly by dampening the local inflammatory response in the skin. Sodium cromoglicate acts as a mast cell stabiliser, preventing the release of histamine and other mediators before they are triggered — making it most effective when used prophylactically rather than after symptoms have begun. Each medication class therefore has a distinct pharmacological role, and combination approaches are sometimes used when a single agent provides insufficient relief.

NHS and NICE Guidance on Allergy Treatment

The NHS and the National Institute for Health and Care Excellence (NICE) provide clear guidance on the management of common allergic conditions. For allergic rhinitis, NICE Clinical Knowledge Summaries (CKS) recommend a stepwise approach: starting with a non-sedating oral antihistamine or an intranasal corticosteroid depending on the predominant symptoms. If nasal blockage is the main complaint, an intranasal corticosteroid is preferred. If sneezing and itching predominate, an antihistamine may be more appropriate. Combination treatment may be considered if a single agent is insufficient.

For urticaria, NICE guidance supports the use of a non-sedating antihistamine as first line treatment, taken regularly rather than on an as-needed basis for chronic cases. If a standard daily dose provides inadequate control, the dose may be increased — up to four times the standard dose — under medical supervision. Patients whose chronic urticaria remains uncontrolled should be referred to a specialist for consideration of further therapies, such as omalizumab. The MHRA has also issued guidance reminding prescribers and patients that sedating antihistamines should be used with caution, particularly in older adults, due to risks of drowsiness, falls, and cognitive impairment.

NICE also highlights the importance of allergen avoidance as a complementary strategy alongside medication. Patients with hay fever, for example, are advised to:

• Check pollen forecasts and limit outdoor activity on high-pollen days

• Wear wraparound sunglasses outdoors

• Shower and change clothes after being outside

• Keep windows closed during peak pollen times

For children, the NHS recommends age-appropriate antihistamine formulations and advises parents to consult a pharmacist or GP before starting treatment in young children — particularly those under two years of age. NICE does not currently recommend routine allergy testing in primary care for mild, well-controlled allergic rhinitis.

Allergen immunotherapy (subcutaneous or sublingual) is a specialist-initiated treatment for selected individuals with severe allergic rhinitis that is not adequately controlled with optimal pharmacotherapy and allergen avoidance. It is not a first line option and should only be commenced under specialist supervision.

Side Effects and Safety Considerations

Whilst first line allergy medications are generally well tolerated, it is important for patients and healthcare professionals to be aware of potential side effects and safety considerations.

Non-sedating antihistamines such as cetirizine and loratadine are associated with relatively few adverse effects. However, some individuals may still experience mild drowsiness, dry mouth, headache, or gastrointestinal upset. Fexofenadine 120 mg is considered among the least sedating of the commonly used antihistamines. Patients taking fexofenadine should be aware that fruit juices (such as grapefruit, orange, or apple juice) can significantly reduce its absorption and should be avoided around the time of dosing. Fexofenadine levels may be increased by medicines such as erythromycin or ketoconazole; patients taking these should seek pharmacist or GP advice. Patients with significant renal impairment should seek advice before using fexofenadine.

Sedating antihistamines (e.g., chlorphenamine, promethazine) carry a higher risk of:

• Drowsiness and impaired concentration — patients should be advised not to drive or operate machinery

• Anticholinergic effects — including urinary retention, constipation, and blurred vision

• Increased fall risk in elderly patients

• Potentiation by alcohol — alcohol should be avoided when taking sedating antihistamines

Regarding use in young children: promethazine is contraindicated in children under two years of age. Chlorphenamine has licensed use from one year of age in some formulations — however, parents and carers should always follow the product-specific label or SmPC and seek pharmacist or GP advice before use in young children.

All patients taking any antihistamine — including non-sedating formulations — should avoid driving or operating machinery if they feel drowsy.

Intranasal corticosteroids, when used as directed, have an excellent safety profile due to minimal systemic absorption. Occasional local side effects include nasal dryness, epistaxis (nosebleeds), and mild irritation. Patients should be advised to direct the spray away from the nasal septum to reduce the risk of bleeding, and to use the lowest effective dose. If recurrent nosebleeds occur, patients should seek pharmacist or GP advice. Long-term use at recommended doses is considered safe for most adults and children over the age specified on the product label.

For pregnancy and breastfeeding: cetirizine and loratadine are among the antihistamines most commonly considered when treatment is needed during pregnancy or breastfeeding, and some intranasal corticosteroids are also used. However, patients should always confirm suitability with a pharmacist or GP and follow product labels, as individual circumstances vary.

Suspected side effects from any allergy medication should be reported via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or via the Yellow Card app. Any concerns about medication interactions or suitability should be discussed with a pharmacist or GP.

When to Seek Further Medical Advice

Most mild to moderate allergic symptoms can be effectively managed with first line allergy medication available from a pharmacy. However, there are important situations in which patients should seek further medical advice from their GP or, in emergencies, call 999 or attend an A&E department.

Contact a GP if:

• Symptoms are not adequately controlled after two to four weeks of appropriate first line treatment

• Allergy symptoms are significantly affecting sleep, work, or daily activities

• There is uncertainty about the cause of the allergic reaction

• Symptoms suggest a more complex condition, such as non-allergic rhinitis, chronic urticaria, or asthma triggered by allergens

• Allergic rhinitis is affecting asthma control

• A child's symptoms are worsening or not responding to age-appropriate treatment

• There is a suspected drug allergy or reaction to a new medication

• New or recurrent food-related symptoms occur

Seek emergency care immediately if any of the following occur, as these may indicate anaphylaxis — a severe, life-threatening allergic reaction:

• Sudden difficulty breathing or wheezing

• Swelling of the lips, tongue, or throat

• Rapid or weak pulse

• Dizziness, collapse, or loss of consciousness

• Widespread rash combined with any of the above

Patients who have previously experienced anaphylaxis should be under the care of an allergy specialist and carry two in-date adrenaline auto-injectors at all times. They should receive training in how and when to use them, and have a written emergency action plan in place. GPs may refer patients to NHS allergy clinics for formal allergy testing, immunotherapy assessment, or specialist management when first line measures have proved insufficient. Early and appropriate use of first line allergy medication, combined with awareness of warning signs, supports safe and effective allergy management.

Frequently Asked Questions