Pili annulati with fragility: Electron microscopic findings of a case

Abstract

Pili annulati (PA) is typically characterized by shinny beads seen along the hair shaft. PA is accepted to belong to the classification of hair shaft abnormalities without fragility. Herein, we described a 14-year-old, fair skin with dark-haired girl diagnosed as PA with fragility which was demonstrated by weathering features in electron microscopic examinations. The patient had shinny beaded, easily breakable hairs since the age of four. A few broken hairs were observed by a light pull test. Transmitted light microscopy revealed periodic dark bands in the hair shaft. These dark bands disappeared after application of 10% aqueous potassium hydroxide. Multiple cavities within hair shaft and severe cuticular damages representing the weathering pattern were observed in electron microscopic examinations. All these findings were found to be consistent with presence of fragility in PA. This case provides evidences of fragile hair structure of PA which may be due to pathological cavities within hair shafts.

Pili Annulati with Severe Trichorrhexis Nodosa: A Case Report and Review of the Literature

“…PA is generally classified as a hair shaft disorder without fragility [5]; however, there are a few reports describing increased fragility and breakage in patients with PA [3,[6][7][8]. These reports describe indentations, cracking, and folding of the hair shaft.…”

Pili Annulati and Trichorrhexis Nodosa in the Same Patient: Cause or Coincidence?

“…Not all hairs are affected and the same follicle may present intermittent involvement. Even though PA is classically not associated with increased hair fragility, a review of the English literature revealed 6 cases of PA and increased hair fragility [1,2,5,6], and two different theories have emerged to explain these cases.…”

“…Two different studies [5,6] detected cuticular damage in shafts with PA by using scanning electron microscopy. The cause of this finding as well as the origin of the cavities themselves are not known, but this abnormality could explain an increased susceptibility to weathering of PA-affected shafts.…”

Trichoscopy of Hair Shaft: White Nodules

“…The other characteristics of the hair are maintained-growth and tensile strength, for example -and, thus, the AP is classified as a change of capillary stem without fragility. The scalp is the most frequently affected region, but other regions can also be affected [5].…”

“…The diagnosis of these hair shaft abnormalities is usually done by microscopy [4] or electron microscopy of the affected hair, but can also be done by trichoscopy [5]; wherein each of these methods has its merits and demerits [6]. Besides being a rapid, easy and more comfortable for the patient-there is not the need to tear or cut the hair for diagnostic procedures, a study published in 2008 by Rakowska demonstrated that trichoscopy gives results comparable to a microscopic examination and concluded that in all the hair shaft abnormalities, except for tricodistrofia, the diagnosis can be made based solely on trichoscopy directly in the dermatologist 's office, reinforcing it as an important tool in practice dermatologist and clinical diagnosis of hair diseases [4].…”