Not all patients with allergies or asthma are candidates for allergy shots. The process is time consuming and not effective for everyone. Physicians generally will try other forms of treatment – such as medications or lifestyle modification measures designed to reduce exposure to allergens – before recommending immunotherapy. A physician may recommend allergy shots if patients:

• Have been unsuccessful with other forms of therapy such as lifestyle changes or allergy medications.
  
  
• Are unable to tolerate the side effects of allergy medications.
  
  
• Suffer with symptoms related to their allergy for all or most of the year.
  
  
• Find that they cannot avoid the allergen in their daily lives.
  
  
• React to airborne allergens, including pollens, dust, molds and animal dander.
  
  
• Experience multiple complications from their allergies, including headache, asthma, allergic conjunctivitis and sinus or ear infections.
  
  
• Are allergic to insect stings. Many individuals have life-threatening reactions to insect stings, making immunotherapy a vital option.

Allergy shots may also be used to treat cases of allergic asthma in children. This can result in a reduction of symptoms and less need for allergy medications in those whose allergies trigger asthma symptoms.

In some cases, when a patient with a drug allergy urgently requires that specific drug, desensitization may be attempted. However, the process can be dangerous, and a physician usually will prefer using an alternate drug.

Allergies that do NOT respond well to immunotherapy include those related to the following allergens:

• Foods or food additives
• Feathers and kapok (mattress filling)

In addition, hives and eczema do not respond well to allergy shots. Therefore, people whose allergies primarily cause skin rash symptoms may not be candidates for allergy shots. However, hives or eczema that is associated with allergic rhinitis or asthma may disappear after allergy shots have been given for those conditions.

The vast majority of patients whose conditions warrant immunotherapy respond favorably to the treatment. In some cases, patients may still be largely symptom-free years after their last allergy shot.

For a smaller percentage of patients, allergy shots are not effective in treating their condition. Individuals who have allergies to many different allergens are less likely to benefit from immunotherapy.