Pigmentary demarcation lines associated with pregnancy

Abstract

We report three cases of pigmentary demarcation lines associated with pregnancy. In addition, we reviewed 19 cases including our 3 cases, which were reported in Japan. Most cases occurred during the latter period of pregnancy (after the seventh month), and the pigmentation faded spontaneously or disappeared a few months after delivery in all cases except one. Pigmentary demarcation lines are classified into five groups (types A-E). Of the 19 cases we reviewed, 2 cases showed lines of both types A and B, whereas all the other cases showed type B lines. Although there have only been 29 cases of pigmentary demarcation lines associated with pregnancy reported to date, before ours, we experienced 3 cases within 3 months, therefore it is possible that many such cases are overlooked. Pigmentary demarcation lines are mainly a cosmetic problem. Two of our three cases presented to obstetricians initially. We suggest that dermatologists should be aware that pigmentary demarcation lines may be associated with pregnancy.

Type B Pigmentary Demarcation Lines of Pregnancy Involving the Anterior Thighs and Knees

“…Furthermore, the involved areas of the anterior thighs and knees in our case do not correspond to the innervation of S1 and S2. To our knowledge, there have been two reports on PDLs with erythematous changes3,8. Mild basal layer pigmentation was observed in previous reports of PDLs that examined the biopsies, histopathologically8.…”

“…Recently, it was suggested that these lines may occur on the face, and additional categories F, G, and H have been suggested2. Type B PDLs are more commonly associated with pregnancy, and are mostly known to occur after the seventh month of pregnancy3. We present a case of type B PDLs of pregnancy, with three interesting main features: 1) a relatively early onset at the end of the fourth month of pregnancy, 2) association of erythematous changes, and 3) unique distribution, involving both the anterior and the posterior aspects of the lower extremities.…”

Voigt‐Futcher pigmentary demarcation lines

“…In some cases, facial PDLs can merge with the periorbital pigmented circle. The skin biopsy specimen in PDLs (type B) shows a slight lymphocyte infiltration around vessels in the upper dermis with mild basal layer hyperpigmentation . In another study, basal and suprabasal pigmentation with mild pigment incontinence in papillary dermis was evident histologically; there may be only increased melanization .…”

“…They may correspond to areas of peripheral cutaneous innervations, pigmentary mosaicism, or cutaneous nerve distribution . An enlarged uterus in the latter period of pregnancy may compress the peripheral nerves originating from the S1 and S2 levels of the spine and obstruct the innervated cutaneous microvasculature causing excessive pigmentation . Inflammation of cutaneous nerves during pregnancy has also been postulated as a cause.…”

Dermatologic conditions in patients of color who are pregnant

“…The pigmentary change may be more obvious in the SOC population (Nakama et al 2009). Melasma (chloasma) is the most cosmetically disturbing form of hyperpigmentation and occurs during up to 75% of pregnancies (McHugh and Laurent 1989).…”