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Updated: Mar 31, 2026
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Characterization of In Vitro Differentiation of Human Primary Keratinocytes by RNA-Seq Analysis
Published on: May 16, 2020
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Porokeratosis ptychotropica
Linda Y S Jans1, Sebastiaan A S van der Bent1
1Department of dermatology, Alrijne Hospital, Leiden, The Netherlands.
The British Journal of Dermatology
|March 30, 2026
Summary
A rare skin condition, porokeratosis ptychotropica, presented as itchy, discolored bumps in the perianal area for two decades. Histology confirmed the diagnosis, revealing characteristic skin changes.
Area of Science:
- Dermatology
- Histopathology
Background:
- Porokeratosis ptychotropica is a rare variant of porokeratosis.
- It typically affects the perianal and intertriginous areas.
- Lesions are often chronic and resistant to treatment.
Purpose of the Study:
- To report a case of porokeratosis ptychotropica.
- To highlight the clinical and histological features of this rare condition.
Main Methods:
- Clinical presentation of a 70-year-old male patient with a 20-year history of perianal lesions.
- Histopathological examination of skin biopsy.
- Diagnosis based on clinical and histological findings.
Main Results:
- The patient presented with pruritic, hyperpigmented, flat papules and annular plaques with squamous borders in the perianal region.
- Histology showed characteristic cornoid lamellae, underlying dyskeratosis, and a sparse perivascular lymphocytic infiltrate.
- The diagnosis of porokeratosis ptychotropica was established.
Conclusions:
- Porokeratosis ptychotropica is a rare but distinct clinical entity.
- Characteristic histological features are crucial for diagnosis.
- This case underscores the importance of considering rare diagnoses in chronic, treatment-resistant skin conditions.
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