Circumscribed palmo-plantar hypokeratosis: a disease of desquamation? Immunohistological study of five cases and literature review.
BACKGROUND
Circumscribed palmoplantar hypokeratosis (CPH) is a recently recognized, rarely reported dermatosis that shows characteristic clinicopathological features; however, its pathogenesis remains unknown.


OBJECTIVE
The aim of this study was to get further insight into the pathogenesis of CPH.


METHODS
An immunohistological study was performed on five cases of CPH to investigate the expression of several epidermal proliferation and differentiation proteins, with emphasis on those involved in corneocyte desquamation [including corneodesmosin, kallikrein 5 and lympho-epithelial Kazal type inhibitor (LEKTI)].


RESULTS
In three of five cases, a decreased expression of LEKTI, corneodesmosin and filaggrin was found, along with an increased expression of kallikrein 5 and keratin 6. The expression of several other antigens (including involucrin, Ki67, p63, CD138/syndecan I, EGF-R) did not present a consistently different pattern as compared with the unaffected epidermis.


CONCLUSIONS
The immunohistopathologic features of CPH suggest that an altered (accelerated) corneocyte desquamation process could be the main pathological mechanism underlying the development of lesions.
Kanitakis
J
J
Department of Dermatology (Pav. R) and Laboratory of Dermatopathology (Bldg 10), Ed. Herriot Hospital, Lyon cx 03, France. jean.kanitakis@univ-lyon1.fr
Lora
V
V
Chouvet
B
B
Zambruno
G
G
Haftek
M
M
Faure
M
M
D000369:Aged, 80 and over; D049109:Cell Proliferation; D004817:Epidermis / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D000091344:Filaggrin Proteins; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007381:Intermediate Filament Proteins / Q000378:metabolism; D007610:Kallikreins / Q000378:metabolism; D053553:Keratin-6 / Q000378:metabolism; D007645:Keratoderma, Palmoplantar / Q000378:metabolism* / Q000473:pathology*; D008875:Middle Aged; D053491:Proteinase Inhibitory Proteins, Secretory / Q000378:metabolism; D000074163:Serine Peptidase Inhibitor Kazal-Type 5
C109656:CDSN protein, human; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D007381:Intermediate Filament Proteins; D053553:Keratin-6; D053491:Proteinase Inhibitory Proteins, Secretory; C120650:SPINK5 protein, human; D000074163:Serine Peptidase Inhibitor Kazal-Type 5; C400147:KLK5 protein, human; D007610:Kallikreins