Pruritic Periumbilical Plaque as a Presentation of a Rare Perforating Dermatosis

Perforating dermatoses are characterized by transepidermal elimination of altered dermal components or foreign particles. Owing to their common clinical presentation as umbilicated papules with a keratotic plug, histopathology and special staining play a very crucial role in the diagnosis. Perforating calcific elastosis, (periumbilical perforating pseudoxanthoma elasticum), an uncommon acquired localized cutaneous dermatoses, is characterized by transepidermal elimination of modified elastic fibres. It is usually seen in middle-aged obese multiparous women as well-defined periumbilical hyperpigmented atrophic plaques. We report a case of a 66-year-old female who presented with a mildly pruritic hyperpigmented periumbilical plaque of 2 years duration. Histopathology studies revealed multiple fragmented, thick, short, and curly eosinophilic fibers; along with granular basophilic material in the dermis, which stained positive for calcium and elastin, thus clinching the diagnosis of perforating calcific elastosis. There were no features of hereditary pseudoxanthoma elasticum. We report this case for its rarity.