Introduction

Monosensitisation is commonly defined as sensitisation to a single allergen; however, increasing diagnostic resolution has challenged this traditional interpretation.

Aim

We systematically evaluated three operational levels of monosensitisation in fur animal allergy: restriction to a single allergen source (species level), to a protein family, or to a single allergen component.

Material and methods

A retrospective analysis was conducted on anonymised results from two multiplex molecular platforms, ImmunoCAP ISAC (n = 1,133) and Allergy Xplorer–ALEX (n = 420), performed in 1,553 patients with suspected allergic disease. The datasets were analysed separately.

Results

Monosensitisation at the species level was observed for all animal species included in ISAC and for five species in ALEX, with cat and dog predominating. At the protein-family level, exclusive sensitisation to animal lipocalins occurred in 17.87% (ISAC) and 17.5% (ALEX), whereas monosensitisation to serum albumins was less frequent. At the molecular level, single-component sensitisation was largely driven by Fel d 1 in cat sensitisation and Can f 5 (or its ALEX analogue, Can f_male urine) in dog sensitisation.

Conclusions

These findings demonstrate that monosensitisation is a resolution-dependent construct and underscore the importance of diagnostic granularity for accurate phenotyping and precision-guided management in animal allergy.