Multiple Milia as an Isolated Skin Manifestation of Dominant Dystrophic Epidermolysis Bullosa: Evidence of Phenotypic Variability

Multiple milia formation in blistering diseases

BACKGROUND

Milia are superficial keratinous cysts seen as pearly white, dome-shaped lesions 1-2 mm in diameter. Milia are associated with diseases that cause subepidermal blistering, such as hereditary forms of epidermolysis bullosa, epidermolysis bullosa acquisita, bullous pemphigoid, bullous lichen planus, and porphyria cutanea tarda. Multiple eruptive milia are rare and more extensive in number than primary milia.

OBJECTIVE

The aim of this study was to search the literature for cases of blistering diseases with multiple milia formation, especially in areas of the skin where there was no evidence of blistering or trauma, and review the interpretations of their pathogenesis.

METHODS

We performed a literature search with the terms multiple milia and bullous diseases, pemphigoid, and pemphigus.

RESULTS

Very few studies have investigated the origin of milia. Primary milia are thought to originate from the sebaceous collar of vellus hairs, and secondary milia are believed to derive from eccrine ducts more commonly than from overlying epidermis, hair follicles, or sebaceous ducts. Milia secondary to blisters or trauma are speculated to be produced through the regeneration process of disrupted sweat glands or hair follicles. Immunological predisposition, aberrant interaction between the hemidesmosomes, and the extracellular matrix components beneath the hemidesmosomes have been described with regard to the formation of numerous milia during recovery. Multiple milia could be a primary manifestation of dystrophic epidermolysis bullosa in skin areas without evidence of blistering.

CONCLUSION

The exact etiology of multiple milia remains unknown. Immunological predisposition and improper interaction between hemidesmosomes and extracellular matrix components are speculated to play a role in the formation of milia during recovery of bullous lesions in blistering diseases. Still, further studies on the triggering mechanisms of keratinocyte dysfunction in cases of multiple milia formation without evidence of prior blistering are needed.

Inherited Epidermolysis Bullosa – A Case Report of Several Family Members in Three Generations

Inherited epidermolysis bullosa (IEB) is a genodermatosis transmitted in either autosomal dominant or autosomal recessive manner. The disease is characterized by the development of blisters, erosions, scars, nail dystrophy and scalp abnormalities. Our case report has included four members of one family in three generations with manifested disease. Our 25-year-old female patient presented with a few eroded, crusted, nummular lesions localized on the dorsal plate of interphalangeal joints of fingers, elbow and knee skin, while anonychia was found on her digits. Our youngest patient (her 3.5-year-old son) presented with the lesions in the form of blisters filled with serous fluid, erosions, recent scars and atrophy. Some atrophic scars on the elbow and knee skin were found in our patient′s younger brother, aged 16. The 46-year-old mother of our female patient had nail dystrophy on her hands accompanied by the toenails absence. Pediatric geneticist created the pedigree chart which showed autosomal dominant inheritance pattern with complete expressivity and penetrance. Further diagnostics was not done because the family was not interested.