Along with ear infections, Dog Skin Allergies are amongst the most common health problems in dogs.
They are difficult to diagnose as symptoms can be common across many diseases.
Most Allergies are seasonal and the inhalant type, such as tree pollen.
Allergies are usually not able to be cured and therefore need to be constantly managed.
Symptoms of Dog Skin Allergies In most cases, if a dog has an allergy it will be apparent through excessive itching and/or visual skin problems.
Other signs that your dog has an allergy include:

• Chewing on its limbs
• Rubbing its face on the ground or carpet
• Mutiliated, red or sore skin
• Hair loss
• Nasal or eye discharge

Skin Allergy Testing For Dogs There are two types of testing that can be undertaken for dog skin allergies:

• Blood Tests are taken to check for antibodies in the dog's blood that have been triggered by Antigens.
  
• Intradermal Skin Testing is where a small amount of antigen is injected into an area of the dog's skin and observed to determine whether it causes an Allergic Reaction.
  This is the most common form of testing and has a high success rate for identification of Dog Skin Allergies.
  

Alternatively, and more specifically if a Food Allergy is suspected, systematic elimination of items from a dog's diet or environment may help uncover the underlying causes of the allergies.
Dog Skin Allergy Treatments

1. Avoidance - Keep your dog out of grassy fields (keep your lawn mowed short), keep your dog indoors during the pollen season, use humidifiers and keep pets away from you when you are cleaning an area and it is likely to stir a bit of dust (eg vaccuuming).
   
2. Topical Therapy - This involves using "external medications" such as shampoos, rinses and creams for Allergy Relief.
   
3. Antihistamines - Antihistamines have historically been designed for human use and are successful for around only 30% of dogs.
   It is usually recommended to include fatty acids such as Omega 3 in your dog's diet when combined with this treatment to improve the chances of successful allergy relief.
   
4. Steroids - I wouldn't recommend this option except as a last resort.
   The side effects are numerous and the medication is expensive.
   

It is important to note that each dog responds differently to different treatments, but it is wise to be aware of Dog Skin Allergies so that you can ask the right questions of your vet and not blindly accept a recommendation of "drugs" to fix a problem that may be otherwise be eliminated by natural means or a slight modification of your dog's environment.