Histologically, the biopsy specimen from the patient's lower lip demonstrated moderate to prominent collagen deposition within the lamina propria, with overlying atrophy of the epidermis and elongation of the rete ridges. The results of Congo red staining were negative. The results of periodic acid–Schiff staining of the hyaline deposits were positive, consistent with lipoid proteinosis.
Lipoid proteinosis, which is a rare autosomal recessive disorder, was first described by Urbach and Wiethe1 in 1929. It results from a defect in the extracellular protein matrix gene (ECM1), whose product is found in many tissues and plays an integral role in the structural organization of the dermis.2 Although the exact pathogenesis of lipoid proteinosis is unknown, mutations in ECM1 result in reduced or absent expression of ECM1 glycoprotein, leading to aberrant deposition of hyaline material in various tissues.3 Any organ can be affected, but typical locations include the skin and mucosa of the upper respiratory tract. Microscopic characteristicsinclude hyaline deposition within the interstitial connective tissue and thickening of blood vessel walls and basement membrane.4
CARRIE ANN RC, SENAIT WD, JACQUELINE MJ, VINCENT L, KARLA SR. Pocklike Scarring and Sublingual Papules in a Child—Diagnosis. Arch Dermatol. 2008;144(10):1383-1388. doi:10.1001/archderm.144.10.1383-e