Keratosis Punctata Palmaris et Plantaris

Punctate keratoderma‐like lesions on the palms and soles in a patient with chloracne: a new clinical manifestation of dioxin intoxication?

“…Palmoplantar keratoderma of a different type, manifesting as a thickening of the palms and soles associated with sclerodactyly and chloracne, has previously been reported in a weed sprayer exposed to a variety of chloracnegens 11 . The circumscribed hyperkeratoses on the palms and soles in our patient fit the morphological and histological criteria defining KPPP, 13–16 a disorder that also has to be distinguished from the histologically similar keratotic pits, which are confined to the palmar creases 13 . For both conditions, a mechanical trigger for their development is debated 14 .…”

“…14 It has been hypothesized that these lesions represent an abnormality in keratinization of the cells in the intraepidermal sweat duct unit. 15,16 In our patient, histology showed a distinct pattern of a keratotic plug invaginating into the dermis. Keratinization within the duct of the eccrine sweat gland at the periphery of this lesion suggests that, in analogy to the fate of sebaceous glands, squamous metaplasia of eccrine sweat gland cells occurs.…”

“…An autosomal dominant inheritance pattern has been reported for KPPP; 13 however, sporadic cases can occur, 16 sometimes in association with an internal malignancy 14 . The pathogenesis of KPPP is uncertain, but a relationship of the lesions to eccrine sweat glands has been observed by several authors, 13,15 , 16 as well as an association with disorders of keratinization 14 . It has been hypothesized that these lesions represent an abnormality in keratinization of the cells in the intraepidermal sweat duct unit 15,16 …”

Disseminate Palmoplantar Keratodermia with Truncal Lesions

“…Even in the etiologically de fined condition ofthc Richner-Hanhart syn drome, the clinical manifestations are vari able [Zaleski et al, 1973;Goldsmith et ah, 1973;Hanhart, 1947], Hence, many terms like punctate, disseminate and dissipate have been used loosely or interchangeably. Histologically, lesions of punctate PPK show a dense homogeneous and thickened horny layer with keralotic plugs which ex tend downwards producing an undulating appearance of the underlying epidermis [Buchanan, 1963;Coupe and Usher, 1963]. There is mild acanthosis.…”

“…There is mild acanthosis. The granular layer in the depression may be increased in thick ness [Buchanan, 1963;Coupe and Usher, 1963], normal [Galloway and Adamson, 1918;Sweitzer, 1923] or absent [Brown, 1971;Michael, 1933], When it is absent, the overlying horny layer is usually parakeratotic. Occasionally, an extension of a sweat duct in the underlying dermis is seen travers ing the horny layer [Brown, 1971;Coupe and Usher, 1963;Galloway and Adamson, 1918;Sweitzer, 1923], The dermal papillae are usually normal but may be edematous with dilatation of subjacent small vascular channels [Buchanan, 1963;Coupe and Ush er, 1963], These histologic features are also shared by disseminate PPK [Michael, 1933].…”