LAUSR

To the Editor, Voigt‐Futcher pigmentary demarcation lines (VFPDL) are abrupt transition lines between more deeply pigmented skin areas and lighter ones. They are mainly a cosmetic problem, rather common in individuals with darker skin types,1,2 with a female gender pre‐ dilection. Based on their location, pigmentary demarcation lines are classified into eight types (A‐H).3 The pathogenesis of this con‐ dition remains unknown, and at our knowledge, their dermoscopic and reflectance confocal microscopy (RCM) features have not been described. A 33‐year‐old woman of Brazilian origin at the 27th week of her first pregnancy was referred for hyperpigmentation that has been developing for 1 month. On physical examination, we ob‐ served well‐defined hyperpigmented areas on the posterolateral part or her inferior limbs and on the anterolateral part of her arms (Figure 1A,B). On dermoscopic examination, clear borders of abrupt transition could be observed between more and less pigmented skin areas (Figure 1C). Although brown curved lines were noticed in both areas, lines were darker and thicker in the more pigmented areas (Figure 1D,E). Moreover, the background pigmentation was more pigmented in the darker areas (Figure 1D,E). RCM showed that hyper‐reflective keratinocytes were more abundant and reached the upper layers of the epidermis in darker areas compared to lighter ones (Figure 2). Moreover, top of dermal papillae was higher in the darker areas (Figure 2). Atypical melanocytes were not observed. Clinical, anamnestic and instrumental findings were consistent with type A and B VFPDL. Skin biopsy was not performed due to the patient's failure to consent. Most cases of type B pigmentary demarcation lines and few cases of type A occur during the last stages of pregnancy. Their distribution follows the Voigt's lines, which define the distribu‐ tion of peripheral nerves. Although neurogenic inflammation and/or mosaicism are thought to play a role in their development, the aetiology of the disease remains unknown. It has been sug‐ gested that pigmentation could be induced by the compression of the peripheral nerves originating from the S1 and S2 levels of the spinal cord by the enlarged uterus in the latter stages of pregnancy.4 However, this hypothesis does not explain type A of pigmentary demarcation lines that are located on upper limbs. It was also suggested that hyperpigmentation of the specific areas could be triggered by the increase in hormones such as mela‐ nocyte‐stimulating hormone during pregnancy.5 Furthermore,