How antihistamines treat allergies

Medical support for allergies (Allergy medication)

Short version:

  • If an allergy is known, the corresponding allergen should be avoided at all costs.
  • If this is not possible, drugs are used.
  • Which medication is given depends on the type of allergy and the severity of the symptoms.
  • Different allergy medications are available.
  • The only causal treatment for an allergy is allergen-specific immunotherapy.
  • So-called biology are considered to be the hope for future allergy treatment.

Allergy medication

The choice of drug depends primarily on the type of allergy, but also on the severity of the symptoms.


Histamine plays a key role in the development of allergies. Antihistamines block the receptors in the cell that are attacked by histamine, thereby weakening the effect of histamine. Antihistamines are the drugs of choice for mild to moderate symptoms of immediate allergies. They are mainly used for hay fever, itching in connection with allergies, allergic skin diseases, drug allergies and anaphylactic shock.

  • Ointment for application on the skin: relieves itching, reduces eczema and redness
  • Eye drops: for the treatment of itching and redness in the eye
  • Tablet or drops: standard dosage form for the treatment of allergies, but also of urticaria (urticaria / angioedema)
  • Infusion: for anaphylactic shock

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Mast cell stabilizers (Cromone)

Cromone are also anti-inflammatory, but have a weaker effect than antihistamines or cortisone. They inhibit the production of histamine and represent the mildest variant of anti-inflammatory drugs for allergies. They are mainly used for hay fever.

  • Nasal spray
  • eye drop
  • Inhalation solution

Glucocorticoids (cortisone)

Glucocorticoids have anti-inflammatory effects and suppress the immune response. Their effectiveness is primarily based on the fact that they inhibit the activation of inflammatory cells and the formation of inflammatory messenger substances such as histamine and at the same time cause the mucous membranes to swell.

A large number of substances are available in different dosage forms and strengths. They do not work immediately, but only develop their full effect after two to four days. They represent the basic therapy for the control of bronchial asthma and allergic rhinitis in spray form and for the control of eczema in cream / ointment form.

Cortisone for swallowing or as an injection should be reserved for extreme situations (allergic shock, severe shortness of breath) for allergy treatment.

Leukotriene receptor antagonists

Leukotrienes are inflammatory messenger substances that - like histamine - are released by the inflammatory cells and play a role in the development of many symptoms of allergic asthma. Leukotriene receptor antagonists hinder the effect of the leukotrienes and thereby bring about an improvement in the symptoms. In particular, they reduce the narrowing of the bronchi and the excessive build-up of mucus in the airways. Leukotriene receptor antagonists are mainly taken in tablet form and are particularly suitable as basic therapy for mild asthma variants.

Alpha sympathomimetics

Alpha sympathomimetics are used to reduce swelling of the nasal mucous membranes. They have a vasoconstricting, decongestant and secretion inhibiting effect. Since they quickly become dependent, their use should be limited to a maximum of five days.

Beta-2 sympathomimetics

Beta-2 sympathominetics dilate the bronchi by relaxing the smooth muscles in the bronchial wall and are inhaled. They are the basic therapy for bronchial asthma.

Theophylline (xanthine derivatives)

Theophylline dilates narrowed bronchi, making breathing easier. In bronchial asthma, theophylline is taken to prevent seizures.

  • Tablets
  • Injection or infusion


Adrenaline is the most important emergency medication for anaphylactic shock. Its main task is to stabilize blood pressure and circulation. Adrenaline dilates the bronchi and increases blood pressure at the same time. Those affected should practice handling the emergency syringe well so that self-injection can also be carried out in an emergency.

Calcineurin inhibitors

Calcineurin inhibitors are an alternative to cortisone as an anti-inflammatory agent. Their advantage is that they work similarly to cortisone, but are somewhat less effective. Long-term use does not result in thinning of the skin or changes in pigmentation. They are usually used in the form of ointments or creams.

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Allergen-specific immunotherapy

While all other forms of treatment only suppress the symptoms of allergic diseases, allergen-specific immunotherapy is the only causal treatment for allergic diseases. It is known by numerous other names: desensitization, desensitization, allergy vaccination. It is usually carried out over a period of around three years. The most common variants are subcutaneous immunotherapy (SCIT) for injection and sublingual immunotherapy (SLIT) for swallowing in the form of drops and tablets. Not all application variants are available for all allergens. The most common allergens for treatment are house dust mites, plant pollen, bee / wasp venom and some mold spores.

Future of Allergy Treatment

So-called biologics are great hope for the future treatment of allergies. These are biotechnologically produced proteins that can specifically intervene in the immune system and thus prevent the development of an allergic reaction from the outset. Biologics are currently available for the treatment of severe variants of bronchial asthma, neurodermatitis and urticaria (hives). Their disadvantage: they have to be injected and are very expensive.

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Astrid Leitner
Medical review:
Priv.-Doz. Mag. Dr. Stefan Woehrl
Editorial editing:
Mag. Julia Wild

Status of medical information:

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ICD-10: T78.4