Atypical localization of acanthosis nigricans in an obese patient with increased leptin level: is there an association?

Knuckle lesions in inherited and acquired disorders

Skin lesions occurring over the knuckles can be a primary or characteristic manifestation of a disorder. Characteristic knuckle lesions may also be important cutaneous features of various internal disorders when they serve as useful clinical pointers, as well as may speak of the disease severity in certain instances. Furthermore, knuckle lesions also speak of various external factors as the underlying cause of the disease/lesions, such as trauma - occupational or otherwise, and contact dermatitis. Although knuckles essentially imply dorsal aspect of the metacarpophalangeal joints, many of the lesions described as those 'involving the knuckles' are seen over the proximal and/or less frequently, the distal interphalangel joints as well. This review presents a compilation of various inherited and acquired dermatoses and dermatological manifestations of various internal disorders associated with different forms of knuckle lesions.

Is acquired symmetrical acrokeratoderma a new dermatosis? Two case reports and Chinese literature review

BACKGROUND

A series of cases characterized by symmetrical acral hyperkeratosis, mainly involving the dorsal surface of the hands, feet, and wrists, but sparing the palmoplantar areas, as well as rapid immersion upon exposure to water have been recently described in China, but similar disorders have not been reported in the English literature.

METHODS

The clinicopathologic features of two cases of acquired symmetrical acrokeratoderma were reported and 27 Chinese patients were reviewed.

RESULTS

The disorder typically occurred in young or middle aged men. Brown to black hyperkeratotic patches were symmetrically distributed particularly on the wrists and dorsum of hands, fingers, and feet, but without involvement of palms and soles. The lesions became whitish with mild swelling immediately after contact with water and improved generally in winter. Histopathologic examination revealed epidermal hyperkeratosis, acanthosis, and papillomatous hyperplasia, as well as superficial perivascular lymphohistiocytic infiltrate. Main ultrastructural features of the immersed lesion were epidermal hyperkeratosis and spongiosis with partial split of the desmosomes.

CONCLUSION

This disorder may be a new dermatosis, and the term "acquired symmetrical acrokeratoderma" could exactly reflect its clinicopathologic characteristics.