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[Ulstrastructural study of various evolutive stages of pityriasis versicolor (author's transl)]
Abstract:
Small size, less numerous and sometimes clustered melanosomes, were seen within the melanocytes. The others organites alos showed abnormalities: smaller mitochondria, abundant cytofilaments. Sometimes total degeneration of the melanocyte was seen. These alterations are variable, depending upon the evolutive stage of pityriasis versicolor: either hypopigmented undergoing treatment or not, or hyperpigmented. Reactions of several cellular types of the dermoepidermal unit could be observed: more numerous Langerhans cells located near the base of the epidermis, abundant nerve fibers in the superficial dermis and active fibroblasts of foetal type. A slight inflammatory infiltrate was present in some cases. It is suggested that a toxic effect of the fungus is responsible for the changes of the morphological aspects of the melanocyte.
Insights
Pityriasis versicolor causes melanocyte abnormalities, including smaller melanosomes and degenerating cells. These changes, potentially due to fungal toxins, vary with the skin condition's stage.
Area of Science:
- Dermatology
- Mycology
- Cell Biology
Context:
- Pityriasis versicolor is a superficial fungal infection affecting skin pigmentation.
- Melanocyte and dermoepidermal unit cellular dynamics in pityriasis versicolor are not fully understood.
Purpose:
- To investigate the ultrastructural changes in melanocytes and associated dermoepidermal cells during pityriasis versicolor.
- To explore the potential role of fungal toxins in causing these observed cellular alterations.
Summary:
- Melanocytes in pityriasis versicolor exhibit abnormalities such as reduced and clustered melanosomes, smaller mitochondria, and abundant cytofilaments, sometimes leading to cell degeneration.
- The severity of these melanocyte alterations correlates with the clinical presentation (hypopigmented or hyperpigmented) and treatment status.
- Increased Langerhans cells, superficial dermal nerve fibers, and active fibroblasts suggest a complex dermoepidermal response to the fungal infection.
Impact:
- Provides detailed ultrastructural evidence of melanocyte damage in pityriasis versicolor.
- Suggests a fungal toxic mechanism contributing to pigmentary changes in the skin.
- Highlights the intricate cellular interactions within the dermoepidermal unit during this common fungal infection.