Facial lichen striatus.

A 9-year-old girl presented with a 15-day history of abrupt onset of a papular, non-itchy frontofacial rash (figure 1). Her recent anamnesis was negative for contact dermatitis. She had no signs of other dermatological disease (eg, eczema or psoriasis). The rest of the physical examination was normal. The classic appearance and distribution of the rash along Blaschko’s lines (BL) (figure 2) was consistent with facial lichen striatus (LS). LS is a cutaneous disorder characterised by linear papules following a developmental pattern of skin cell precursors (BL), first described in 1901. LS commonly affects children aged 5–15 years, typically occurring on the extremities and trunk, and more infrequently on the face. The facial pattern of BL was described by Happle a century later. Facial LS, similar to ‘classic’ LS, follows a self-limiting course. Evidence for topical steroids and other immunosuppressants for LS is mixed; treatments may accelerate LS resolution (which usually occurs in about 1 year), but some patients may have a limited response. Unlike other cutaneous disorders following BL (linear lichen planus, linear psoriasis, linear lichen nitidus, linear sebaceous/epidermal naevus and blaschkitis), LS is more common in children than in adults and usually does not relapse after resolution. A confirmative biopsy is generally not needed for diagnosis. Comparing the pattern of the lesion to a map of facial BL (see figures 1 and 2) may be useful for paediatricians to confirm the suspicion of facial LS. Thus, body and face BL maps prove to be an important diagnostic tool to assist in the diagnosis of cutaneous disorders, sparing more invasive tests such as biopsy. Enrico Valerio, Chiara Giordano, Simone Mameli, Alessandro Poles, Mario Cutrone Pediatrics and Neonatology Unit, Ospedale “Pietro Cosma”, Camposampiero (Padova), Italy Medical School, University of Padua, Padova, Italy Medical School, University of Perugia, Perugia, Italy Pediatric Dermatology Unit, Ospedale “Dell’Angelo”, Mestre (Venezia), Italy