O que é febre do feno?

Febre do feno is caused by an allergic reaction to pollen. When it comes into contact with the mouth, eyes, nose or throat, the body reacts by making specific antibodies. Hay fever affects people at different times depending on which pollen they are allergic to.

The majority of people are allergic to grass pollen, so will experience their worst symptoms between May and June; tree pollen affects people in late spring between March and May; while others are affected by weed and mould pollens in the autumn.

The condition is characterised by sneezing and tosse, a runny or blocked nose, red watery eyes, itchy throat, mouth, nose, eyes or ears, headaches and sometimes a feeling of fatigue or tiredness. You may also experience a wheeze and tightness in the chest.

Many people manage hay fever symptoms by taking simple steps to stop the pollen reaching them - wraparound sunglasses to protect the eyes, or Vaseline around the nostrils - or by taking over-the-counter antihistamine drops or comprimidos, and using a spray nasal.

Hay fever injections are are banned in the UK. The injection, known as Kenalog, is no longer available on the NHS, due to concerns over the risk of serious side effects. Despite this, some private clinics still administer, so it's important to understand the risks, benefits, and who it's intended for.

Chief pharmacist Stuart Gale at Oxford Online Pharmacy says: "Kenalog is only safe and recommended for use in a small number of people, as this type of steroid can make existing medical conditions worse. The mainstay of hay fever treatment is hay fever tablets - called oral antihistamines - nasal sprays and eye drops."

For around 1 in 10 people with hay fever, home and over-the-counter medications aren't enough to relieve their symptoms. In the past, some have turned to the hay fever jab, a steroid injection marketed as Kenalog which works by suppressing the body's immune response to histamines. This in turn relieves symptoms.

Dr Farah Gilani, a Medicspot GP, says "This is an injection of a steroid called triamcinolone into a large muscle in the body. Once the steroid is injected, it slowly leaks from the muscle for 3 to 8 weeks and travels throughout the body, theoretically offering relief from hay fever symptoms."

"Once the steroid has been injected, nothing can be done to prevent it from spreading through the body over the following weeks, even if side effects are experienced," states Gilani. "In addition, it may be harmful to some people, such as those who have stomach ulcers, diabetes or an active infection."

Repeated use of steroid medications like the hay fever jab can also lead to bone loss, osteoporosis, and broken bones.

Kenalog is not licensed for treating hay fever in the UK. Charity Allergy UK does not endorse the injection: "The steroid injection is not recommended as it is a high-dose steroid given by an intramuscular injection and once injected, the amount of steroid cannot be removed and it comes with a high side-effect profile.

The UK government is also clamping down on advertisements for the hay fever injection. In 2022, private clinics offering Kenalog were warned that promotional social media posts would be in breach of the law.

1. Sidhu and PREUSS: Triamcinolone.