Introduction. Linear and whorled nevoid hypermelanosis (LWNH) is a disorder of pigmentation characterized by macular hyperpigmentation following the Blaschko lines. Only 50 cases of LWNH have been described so far. Linear and whorled nevoid hypermelanosis may be associated with congenital defects. Underlying chromosomal mosaicism has been demonstrated in only a few published cases. Diagnosis is based on characteristic clinical and histopathological findings.

Objective. Presentation of the first Polish case of LWNH.

Case report. We present a 29-year old Caucasian woman with streaks of reticulate hyperpigmented macules arranged in a whorled pattern over the trunk and extremities. Histopathology showed hyperpigmentation of the epidermal basal layer and prominent melanocytes, without pigment incontinence. Based on clinical and histopathological findings the diagnosis of LWNH was established. Additionally hyper IgE syndrome has been diagnosed in the patient.

Conclusions. In LWNH the therapeutic challenge is the diagnosis and treatment of comorbidities; otherwise it may cause a serious threat to the patient’s health.