Allergies _When -Are -Strong -Antihistamines -Necessary

It’s the start of Spring, and sadly for those with seasonal allergies, the start of several weeks (or even months) of discomfort.

As anyone with hay fever will know, milder weather typically leads to higher pollen levels, which can irritate rhinitis symptoms. Some people with allergic conjunctivitis and allergic skin conditions, such as atopic eczema, may also find that their symptoms are worse during the spring months.

Fortunately help is available in the form of medication. There are a variety of tablets, creams and sprays which can provide relief from symptoms, many of which can be bought over the counter from your pharmacist.

However in some cases where symptoms are severe or persistent, it might be necessary to see a doctor or a specialist, who may choose to issue a prescription medicine to help get symptoms under control.

In this post, we’ll look into this topic further and discuss when allergy symptoms warrant a trip to the GP.

Avoidance measures

Some people with mild allergies may not need to take medication at all, and be able to manage their condition simply by limiting their exposure to irritants.

For instance, someone with a pollen allergy may be able to keep symptoms at bay on high pollen days by:

  • not venturing near grass
  • closing windows and doors when inside
  • getting changed when coming home after being outdoors
  • and not drying laundry outside.

Applying a tiny amount of vaseline to the lower inside of the nostrils can also help to reduce the amount of pollen that makes it into your airways.

However where symptoms persist despite these measures, speaking to your pharmacist about antihistamine treatment may be able to help.

What allergy treatments can I get over the counter?

Several different types of antihistamine treatment can be bought without a prescription, but it's still recommended that you speak to your pharmacist before taking them for the first time, or if your medical circumstances have changed since you last took them. Certain allergy treatments may not be compatible with medications used in treating other conditions, such as muscle relaxants or treatments for hypertension or diabetes.

Piriteze, Zirtec and Claritin are popular examples of over-the-counter antihistamine tablets which can be used to treat allergy symptoms.

Some decongestant nasal sprays such as Sudafed are also available without a prescription. These work by reducing swelling inside the airways, making it easier for the user to breathe during an allergy flare-up. However, they can only generally be used for short periods (up to a few days or a week in most cases) and are not suitable for persons with certain medical conditions. Where symptoms persist, it is advisable to see a doctor, who may prescribe a combination nasal spray, containing a decongestant in addition to an antihistamine or a corticosteroid. Nasal sprays containing antihistamines, such as Rhinolast, tend to be prescription-only.

Combination eye drop treatments, containing both an antihistamine and decongestant agent (such as Otrivine-Antistin) can be purchased over the counter. These are indicated for allergic conjunctivitis caused by hay fever or household allergies.

Topical creams and lotions containing antihistamines are available for the treatment of atopic eczema caused by allergies, but these will generally require a prescription, and will only tend to be used if other treatments have not worked.

When should I see a doctor?

It is recommended that you see your doctor about your allergies if:

  • you have recently developed symptoms or are experiencing them for the first time
  • symptoms persist, or if over-the-counter medicines do not provide sufficient relief
  • they prevent you from going about your normal routine, or interfere with your sleep
  • or you aren’t sure which treatment to take because you are also taking medication for other conditions.

In some cases, your doctor may be able to prescribe a different type of medication to help tackle symptoms. They may also be able to refer you to a consultant allergist for further help if your allergies are having an impact on your life for several months during the year.

How do antihistamines work?

Histamine is a chemical which is generated by the immune system. It is present in the skin and respiratory tract, and helps to heal tissue and defend the body against foreign substances.

The body releases histamine when it detects a threat. However in the case of someone with an allergy, the immune system will treat something harmless such as pollen as a threat, and go into defensive mode. This then causes symptoms we associate with allergies, such as swelling and inflammation.

Antihistamines work by preventing the histamine chemical from binding with receptor cells and activating this immune response. This then reduces the severity of symptoms or, when taken prior to a flare, prevents them from occurring.

What are first, second and third generation antihistamines?

First-generation antihistamines, such as cyclizine and promethazine, are an older type of treatment; whereas second- and third-generation antihistamines, such as cetirizine and desloratadine, are newer forms.

The main difference is that second- and third-generation treatments are not as likely to cause drowsiness as a side effect as first-generation treatments; newer treatments are more ‘selective’ in blocking histamine from binding with receptors (in that they act more exclusively on those in the skin and airways, and not on those in the brain).

For this reason, second- and third-generation tend to be recommended in most cases over first-generation medications; and first-generation versions may be seen as ‘strong antihistamines’ due to their sedative qualities.

However in cases of severe atopic eczema, first-generation or sedating antihistamines may be preferred, particularly if skin irritation is causing sleep disruption.

What if antihistamines don’t work for me?

If antihistamines alone do not work in reducing allergy symptoms, then a GP or allergy specialist may choose, where suitable, to issue a different type of treatment.

Some prescription nasal sprays and eye drops for allergies may combine an antihistamine with a decongestant, or a corticosteroid (such as Dymista).

Decongestants function by reducing swollen blood vessels, and this helps to clear the nasal passages. As previously mentioned, they are typically only used as a short-term treatment.

Corticosteroids work by inhibiting the body’s immune response, and in allergies help to reduce inflammation.

In some cases, where someone requires urgent, fast-acting relief and other medications have not responded, a doctor may choose to issue corticosteroid tablets. However, corticosteroid tablets will only be issued in exceptional cases for allergies, and shouldn’t be used for long periods, due to their risk of side effects.

If you are experiencing allergy symptoms and are not sure which treatment is the most suitable for your condition, your GP or local pharmacist can help.