Follicular Dowling Degos disease: A rare variant of an evolving dermatosis.

Dowling Degos disease is a rare, reticulate pigmentary disorder with variable phenotypic expression that manifests as hyperpigmented macules and reticulate pigmentary anomaly of the fl exures. Many variants of this condition and its overlap with other reticulate pigmentary disorders have been reported in the literature. We present here two cases of DDD with follicular localization, both clinically and histologically. It was associated with ichthyosis vulgaris in one case. Follicular DDD is an uncommon variant of this evolving dermatosis. Our report supports the possible role for disordered follicular keratinisation in its pathogenesis.

Reticulate pigmentary disorders.

Reticulate pigmentary disorders is a term that is loosely defined to include a spectrum of acquired and congenital conditions with different morphologies. The presentations vary from the reticular or net like pattern to the" freckle like" hyper and hypopigmented macules that are usually restricted to the true genetic "reticulate" pigmentary disorders. There is little clarity on this topic and related terms, in major dermatology textbooks. Hence, to harmonize the different entities we feel that the term "mottled pigmentation" could be used to include reticulate pigmentary disorders (acquired and congenital), dyschromasias and the disorders with a reticular pattern. The genetic reticulate pigmentary disorders can also be classified according to the gene loci which in the majority of cases are localized to keratin 5/14. A more useful clinical method of classification is based on the regional distribution, which includes facial, truncal, acral or flexural types. In this review we will largely focus on the inherited reticulate pigmentary disorders.