Comprehensive morphological characteristics of skin lesions in children with an undetermined clinical picture of dermatosis in comparison with typical forms of psoriasis and atopic dermatitis in children and adults

Introduction. The literature increasingly describes an atypical clinical picture of psoriasis and atopic dermatitis (AD) in children, combining the features of both diseases. Histological examination conducted as part of a comprehensive diagnosis in such cases does not provide an unambiguous answer in favor of one or another disease, presenting an undetermined morphological picture in comparison with the classical forms of psoriasis and AD. At the same time, the classical morphological criteria for psoriasis and AD were described without considering the age of patients, so it remains unclear whether morphological criteria for adults can be used in the diagnosis of skin pathological process in children. Aim. To characterize the pathomorphological changes in the skin lesions of children with an undetermined clinical picture (UCP) of the disease in comparison with changes in the inflammatory skin lesions with a typical clinical picture of psoriasis and AD in children and adults. Materials and methods. A comparative morphometric study of skin biopsies of children and adults of 6 groups was performed : 2 groups of adult psoriasis and AD patients; 2 groups of children with a typical clinical picture of psoriasis and AD confirmed histologically; a group of children with UCP of the disease (without typical morphological signs of psoriasis and AD); the last, 6th group, comprised biopsies of children’s skin obtained during surgical procedures for non-dermatological diseases. Results. The comparative morphometric analysis of the skin biopsies showed that in typical psoriasis, the structural changes in the epidermis of children and adults were the least. In AD, the structural differences of the skin lesion morpho¬logy in children and adults are more pronounced. The inflammatory infiltrate cellularity in the children’s groups was lower than in adults with the same diseases and had a higher count of lymphocytes. At the same time, the skin lesions in children with UCP had more morphological features in common with the skin lesions of children in other groups than with those of adults. Conclusion. According to the selected classical criteria, the structural changes of the epidermis in children with UCP occupied an intermediate position between the psoriasis and AD groups and had more morphological features in common with the skin lesions in other children groups. However, the peculiarity of the inflammatory infiltrate found in skin lesions in UCP of the disease requires further investigation.