Granular parakeratosis - a clinical-pathological correlation of 10 cases

• Published in: Journal der Deutschen Dermatologischen Gesellschaft 2009-04, Vol.7 (4), p.340-344
• Main Authors: Braun-Falco, Markus, Laaff, Helmut
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Hailey-Hailey disease; Humans; intertriginous eczema; Keratosis - classification; Keratosis - pathology; lichen planus; Male; Middle Aged; psoriasis inversa
• ISSN: 1610-0379; 1610-0387
• DOI: 10.1111/j.1610-0387.2008.06964.x

Summary Background: Granular parakeratosis describes chronic skin lesions within the intertriginous areas that demonstrate microscopically parakeratosis together with retention of keratohyalin granules within a thickened stratum corneum. Granular parakeratosis is rarely diagnosed, since it is still relatively unknown within the differential diagnoses of intertriginous eruptions, and a skin biopsy is required for diagnosis. In order to gain insight into the clinical‐histopathologic correlation, we present 10 cases of granular parakeratosis. Methods: The files of the DermatoHistologisches Labor Dr. H. Laaff, Freiburg, were searched for the diagnosis of granular parakeratosis. Identified cases were evaluated for clinical information and histopathologic characteristics. Result: From 2004 to 2007 10 cases (7 women, 3 men) of granular parakeratosis were found corresponding to a frequency of 0.004%. The average age was 62 (33–82). In women lesions occurred in submammary region (4), axillae (2) and popliteal fossa; in men, groin (2) and genital region. Clinically two different patterns are recognized – lichen planus‐like red‐brown slightly hyperkeratotic or scaly papules, and larger plaques which are either bright red shiny or grey‐brown with lichenification. Histologically the typical granular parakeratosis was seen in a prominently thickened stratum corneum. It remains unclear whether granular parakeratosis is a disease entity or whether it reflects a reaction pattern to unknown stimuli.