Clinical comparison of human and canine atopic dermatitis using human diagnostic criteria (Japanese Dermatological Association, 2009): Proposal of provisional diagnostic criteria for canine atopic dermatitis

Atopic dermatitis (AD) is a common skin disease encountered in both humans and dogs. Canine AD can be used in the analysis of naturally occurring AD; however, details of clinical comparison have been lacking. The purpose of this study is to compare those clinical features using the human diagnostic criteria (Japanese Dermatological Association, 2009). Fifty-one dogs with canine AD were evaluated by the human criteria. Prior to this study, canine AD was basically diagnosed by the fulfillment of two authentic canine AD criteria and a positive reaction against Dermatophagoides farinae in serum immunoglobulin E levels and/or in intradermal tests. Among the human AD criteria items, behavior corresponding to pruritus was observed in all 51 dogs. Skin lesions corresponding to eczematous dermatitis were seen in 50 dogs, and symmetrical distribution of skin lesions was noted in all 51 dogs. A chronic or chronically relapsing course was observed in 50 dogs. Based on these results, the concordance rate for the criteria was 96% (49/51). Differential diagnoses of AD were also investigated in the same manner. The concordance rate for the criteria was 0% (0/69) in scabies, 2% (1/50) in pyoderma, 0% (0/50) in demodicosis, 0% (0/9) in cutaneous lymphoma, 0% (0/2) in ichthyosis, 25% (2/7) in flea allergy, 48% (24/50) in seborrheic dermatitis and 75% (3/4) in food allergy. Canine AD is thus indicated as a valuable counterpart to human AD in clinical aspects. In addition, the human AD criteria could be applicable, with some modification, as provisional diagnostic criteria for canine AD.