Peripilar hair casts

https://doi.org/10.1016/j.jaad.2015.10.032Get rights and content

Section snippets

Clinical presentation

A 7-year-old girl who wore a tight ponytail every day presented at our dermatology clinic with whitish particles bound to the hairs of her scalp, a problem that had existed for a number of months (Fig 1). Pediculosis capitis was suspected by the physicians who attended her at another clinic, and permethrin shampoo was prescribed on several occasions. However, no improvement was seen.

Dermoscopic appearance

Polarized light dermoscopy revealed small, bright, long and tubular, whitish structures of 1 to 2 mm surrounding multiple hair shafts in distal, medial, and proximal positions (Fig 2). They could be easily moved along the affected hairs.

Key message

The child was diagnosed with peripilar keratin casts, which are commonly misidentified as head louse eggs. However, the latter appear as round particles bound to the sides of the hair shafts, whereas peripilar casts appear as cylindrical tubular

References (2)

Cited by (0)

Publication of this article was supported by 3Gen Inc.

Funding sources: None.

Conflicts of interest: None declared.

View full text