Pigmentary Demarcation Lines of Pregnancy with Erythema

Abstract

We describe two patients with pregnancy-associated pigmentary demarcation lines overlapped by erythematous changes. In both cases, there was a symmetrical well-defined erythematous pigmentation involving the buttocks and flexor aspects of the legs. After normal delivery the erythema disappeared within 7–10 days, follwed by slow resolution of the pigmentation. Compression by the enlarged uterus of peripheral nerves issuing at S₁––S₂ is proposed as a mechanism of these changes.

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.…”

“…The erythematous changes in our patient may have resulted from the alteration of estrogen levels in pregnancy. Compression of peripheral nerves emerging from S1 and S2 levels by the enlarged uterus and resulting erythema, pigmentation from neurogenic inflammation has also been suggested8. However, PDLs are not associated with specific symptoms.…”

A Copy Editor Has No Right to Distort an Author's Meaning—Reply

“…6 Compression of peripheral nerves issuing at the space between S1 and S2 by the enlarged uterus has been proposed as a causative mechanism of these lines. 7 Some cases of pregnancy-associated PDLs were accompanied or preceded by an overlapped erythematous component, and the fact that erythema and pigmentation disappeared soon after delivery supports this hypothesis. 7 Furthermore, type B PDLs may not appear in all of a woman's pregnancies 1,4 and may be present only for a limited time during pregnancy, especially at the end.…”

“…7 Some cases of pregnancy-associated PDLs were accompanied or preceded by an overlapped erythematous component, and the fact that erythema and pigmentation disappeared soon after delivery supports this hypothesis. 7 Furthermore, type B PDLs may not appear in all of a woman's pregnancies 1,4 and may be present only for a limited time during pregnancy, especially at the end. This finding may be explained by the possible presence of a local trigger factor occurring only in some pregnancies or during some periods of the same pregnancy.…”

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