Pharmacotherapy of Allergic Diseases

• Subjects from all countries, ethnic and socio-economic groups, and ages suffer from allergies.

• Asthma and allergic rhinitis are common health problems that cause major illnesses and disability worldwide.

• The strategy to treat allergic diseases is based on: (i) patient education, (ii) environmental control and allergen avoidance, (iii) pharmacotherapy, and (iv) immunotherapy. 

• Pharmacotherapy is the mainstay of treatment for allergic diseases because it not only controls symptoms but improves the quality of life.

• Primary care physicians play an important role in first line management of allergies. They have to make the initial clinical diagnosis, begin treatment, and monitor the patient. 

• Allergy specialists are trained to make a specific diagnosis and treat patients with allergies, particularly those with moderate/severe disease.

• The chronic nature of allergies makes it essential to propose and explain long-term management strategies to patients, health care policy makers, and government authorities. 

• In recent decades, a substantial improvement has been made in the efficacy and safety of allergy pharmacotherapy. 

• Disease management using evidenced-based practice guidelines has been shown to yield better patient outcomes.

Allergen Specific Immunotherapy

• Allergen specific immunotherapy is recognized as an effective treatment for respiratory allergy and Hymenoptera venom allergy. 

• Subcutaneous Immunotherapy (SCIT) represents the standard modality of treatment. Sublingual Immunotherapy (SLIT) which is now accepted as an alternative to injection immunotherapy, has recently been introduced into clinical practice. 

• The additional effects of allergen specific immunotherapy, that are lacking with pharmacological treatment, are the long-lasting clinical effects and the alteration of the natural course of the disease. This prevents the new onset of asthma in patients with allergic rhinitis and prevents the onset of new sensitizations. 

• The mechanisms of action of specific immunotherapy are multiple and complex, and result in a modification of the immunological responses to allergens, with subsequent reduction of the allergic inflammatory reaction. The mechanisms of action of SCIT and SLIT are similar.

• SCIT maintains its beneficial effects for years after it has been discontinued. This long-term or carry over effect also occurs with SLIT. 

• SCIT indications, contraindications, limits and practical aspects are defined in numerous guidelines. 

• SLIT is considered a viable alternative to SCIT and is used in clinical practice in many countries. A 2009 World Allergy Organization Position Paper further details the indications, contraindications, and methodology of using SLIT.

• New forms of immunotherapy, allergen products, and approaches to food allergy and atopic eczema are under investigation.

Biological Agents 

• Research in allergy and immunology has led to a variety of novel therapeutic approaches; some agents are already utilized in clinical practice and more are in clinical trials. 

• New therapeutic approaches include toll-like receptor agonists, cytokine blockers, specific cytokine receptor antagonists and transcription factor modulators targeting syk kinase, peroxisome proliferator-activated receptor gamma, and nuclear factor kappa B. 

• The anti-IgE mAb omalizumab is effective to treat allergic asthma, but the criteria to select patients for this type of therapy are not well-defined.