Atopic dermatitis (AD) is characterized by exacerbations and reductions of eczematous skin, caused by impaired skin barrier and aberrant Th2-type and Th-22 cytokine production. A number of allergens, particularly in contact with fur animals might aggravate the disease. 

The following study had sought to define the effect of having a regular contact with a pet cat at home on the severity of symptoms and signs of AD. The issue was addressed using the SCO Ring Atopic Dermatitis (SCORAD) and visual analog (VAS) scores. It evaluated the intensity of pruritus by measuring the blood content of specific IgE and IL-4, IL-13, and IL-22 cytokines. The study group included 47 adult patients suffering from AD from childhood. Out of them, 18 participants declared having a regular contact with a cat and the remaining 29 participants denied it. A control group was also included consisting of 16 healthy volunteers with no signs of AD. 

The SCORAD and VAS scores were significantly higher in patients who had contact with a cat than in those without did not had any contact (median SCORAD 61.0 vs. 50.4 and VAS 9.0 vs. 4.0 points, respectively). The sIgE of a majority of patients (94.4%) in contact with a cat was in Class V-VI, compared with only few patients (3.4%) with no such contact, having sIgE in the same classes (p < 0.001). Also, IL-22 was a single raised cytokine, seen in the patients in contact with a cat, and it also correlated with pruritus severity. 

Thus, the study results emphasized the need to be careful of the cat fur allergen. They also highlighted the consideration and caution in getting and keeping a pet cat by AD.

Source: Jaworek AK, Szafraniec K, Jaworek M, et al. Cat Allergy as a Source Intensification of Atopic Dermatitis in Adult Patients. AdvExp Med Biol. 2020; 1251:39-47.