Hay fever and allergic rhinitis

Allergic rhinitis is treatable and the standard treatments work well. The herbal options are a step below, and one of them is not safe.

Butterbur has real trials in allergic rhinitis — a randomised trial found it comparable to cetirizine for symptoms with less sedation. It also contains pyrrolizidine alkaloids, which are hepatotoxic, and the plant material has caused liver injury. Only PA-free certified extracts are acceptable, and even then the supply and regulatory problems are real. This is a case where a herb with genuine evidence is still not the first choice.

Stinging nettle has small trials suggesting benefit in allergic rhinitis, of low quality. It is generally safe; the freeze-dried leaf is the form used.

Saline nasal irrigation is the under-appreciated intervention. It reduces symptoms and medication use in allergic rhinitis and rhinosinusitis, and it has essentially no adverse effects. It does not replace the nasal steroid spray; it adds to it.

Vitamin C at high dose has weak and inconsistent evidence in allergic rhinitis.

What actually works, in order. An intranasal corticosteroid (which is the most effective single treatment for most people with allergic rhinitis); a second-generation oral antihistamine; saline irrigation; allergen avoidance where specific (bedding covers for dust mite, keeping windows closed during the pollen peak, showering after outdoor exposure); and immunotherapy for severe cases, which is the only treatment that changes the disease.

The cautions. Oral decongestants raise blood pressure, cause insomnia and are unsafe in hypertension and cardiac disease. Topical decongestant sprays cause rebound congestion (rhinitis medicamentosa) after about 3-5 days of use and are the commonest reason someone's blocked nose never gets better. Do not use them for more than 3 days. And any herb for hay fever — nettle, butterbur, or a supplement — is an addition to the treatments above, not a replacement for a nasal steroid that works.