Pili Annulati Coincident with Alopecia Areata, Autoimmune Thyroid Disease, and Primary IgA Deficiency: Case Report and Considerations on the Literature

Abstract

Pili annulati is a rare autosomal dominant hair disorder clinically characterized by a pattern of alternating bright and dark bands of the hair, the bright bands appearing dark if observed by transmitted light. This pattern is due to the periodic occurrence of air-filled cavities along the hair cortex which scatter and reflect the light while precluding its transmission. A susceptibility region, including a possibly responsible Frizzled gene, has been mapped to the telomeric region of chromosome 12q, although a specific mutation has not been identified. The condition has sometimes been observed in concurrence with alopecia areata, and in this paper we report a case in whom the concomitant severe alopecia areata was associated with autoimmune thyroid disease and primary IgA deficiency – a quadruple complex which, to our knowledge, has never been previously described. The occurrence of multiple immune disorders in the same patient affected by pili annulati could represent a key to understanding the high prevalence of alopecia areata in this condition. Specifically, in individuals predisposed to autoimmune disease, the molecular alterations that cause the anatomical changes of pili annulati could prompt the immune response against the hair root that underlies alopecia areata.

Disorders of Hair

“…• Clinical feature: In this condition, alternating light and dark bands are seen along hair shafts, leading to a speckled-appearing scalp hair (Singh and Miteva 2016). These bands appear as rings if viewed in threedimensional space (Castelli et al 2012). The condition can also affect pubic, beard, and axillary hairs (Akoglu et al 2012).…”

Genetic Hair Disorders: A Review

“…7). These air-filled cavities appear dark on light microscopy [85]. Usually PA is not associated with hair fragility; however, a few cases associated with severe hair fragility have been reported [86,87].…”

“…Furthermore, two patients were described in the literature with pili annulati in whom fragility of hair developed in a causal relationship with the onset of androgenetic alopecia [88]. There are a few diseases that have been reported to be associated with PA including autoimmune thyroid disease and primary immunoglobulin A deficiency [85].…”

Prognosis and Management of Congenital Hair Shaft Disorders without Fragility—Part II

“…Although PA has not generally been found to affect hair fragility, one case did note hair fragility , so dermatologists should not exclude PA in a patient with hair fragility. Disease associations include alopecia areata, autoimmune thyroid disease, and primary immunoglobulin A deficiency .…”