The polysaccharide Pullulan improves the initial steps of allergen-specific immunotherapy in dogs

Allergen-specific immunotherapy (AIT) is the only aetiological treatment for canine atopic dermatitis (CAD). Pullulan, a polysaccharide with immunomodulatory properties, may enhance AIT outcomes when combined with allergens such as recombinant Dermatophagoides farinae 2 (Der f 2). This study evaluated the safety and efficacy of Pullulan-adjuvanted AIT using recombinant Der f 2 or D. farinae (DF) extracts compared with conventional DF extract immunotherapy.

In this prospective, randomised study, 30 client-owned CAD dogs sensitised to DF were assigned to receive either subcutaneous immunotherapy (SCIT) with DF, SCIT with DF plus Pullulan (pSCIT) or Allermmune HDM (Pullulan-recombinant Der f 2). Treatments were administered over 14 weeks. Clinical efficacy was assessed using the canine atopic dermatitis extent and severity index (CADESI), pruritus visual analogue scale (pVAS) and medication score (MS). Safety was evaluated based on reported adverse events.

Four dogs were excluded for reasons unrelated to treatment, leaving 26 dogs for analysis. Baseline CADESI, pVAS and MS did not differ significantly between groups. CADESI scores decreased significantly in the Allermmune and pSCIT groups compared with SCIT, whereas MS and pVAS showed no significant intergroup differences. Age and sex had no significant effect.

Limitations include the small sample size, absence of a placebo control group, short follow-up period and lack of blinded outcome assessment. Larger controlled studies with extended follow-up and blinded evaluation are warranted to confirm these findings.

Pullulan may enhance AIT efficacy in CAD, supporting its potential role as an immunotherapeutic adjuvant independent of allergen source.