Pruritic urticarial papules and plaques of pregnancy with unique distribution developing in postpartum period.

Dear Editor:

Pruritic urticarial papules and plaques of pregnancy (PUPPP) is one of the most common diseases associated with pregnancy, and is characterized by urticarial papules and plaques with pruritus on the abdomen, buttocks and thighs1. In most cases, the skin lesions develop in the third trimester of primigravida and disappear within 7 to 10 days after labor1. Lesions mostly appear first on the abdomen, and then spread to the proximal extremities. Therefore, the abdomen is involved in most cases, especially the stria distensae. A 30-year-old female patient visited our department due to pruritic erythematous papules and plaques on both arms and both legs (Fig. 1 A~C). She complained that the erythematous skin lesions had first developed on both legs and were very pruritic. The lesions then spread to both arms. The patient's abdomen was spared. She went through labor seven days before the lesions developed in both thighs. She was in a postpartum period, which is the period beginning immediately after the birth of a child and extending for about six weeks. It was her first labor and a single pregnancy. She had no specific medical or dermatological history. We did laboratory studies including complete blood counts, liver function tests, renal function tests, thyroid function tests urinalysis and autoimmune study. She has no specific abnormal findings during these studies. We performed a biopsy of the lower leg for an exact diagnosis. Histopathological findings showed spongiosis of the epidermis, edema of the papillary dermis and perivascular infiltration of lymphocytes and eosinophils (Fig. 1D, E). The results of direct immunofluorescence were negative. The patient began to take prednisolone 20 mg daily for 4 days and then tapered to 5 mg per week. She was also treated with an oral antihistamine and a topical corticosteroid. After two weeks of treatment, the patient's symptoms of pruritus and erythematous skin rash were improved. In most cases, this disorder develops in the third trimester of pregnancy. Tiny pruritic erythematous papules first appear in the striae distensae of the abdomen, and then spread to the buttocks and legs. In our case, multiple pruritic erythematous papules and plaques occurred after labor, and the lesions were limited to the legs and arms, sparing the abdomen. Postpartum PUPPP is very rare (Table 1)2-5. In previous cases, the lesions first developed on the abdomen, and then spread to other parts of the body. In our patient, the pruritic skin lesions were limited to the extremities, while the abdomen was spared. Some previous cases also exhibited unique distributions. In contrast to all these cases, our case spared the abdomen and involved only the extremities. Generally, histological findings of PUPPP showed dyskeratosis, spongiosis of the epidermis, edema of the papillary dermis and perivascular lymphocytic infiltrations1. Direct immunofluorescence studies are negative. We also noted these histological features in our case. Based on these histopathological and clinical findings, we diagnosed the case as PUPPP developed in postpartum-period. Although our case was similar to urticarial vasculitis, clinically, the specimen did not show findings of leukocytoclastic vasculitis, and she improved without hyperpigmentation. Thus, we can rule out the urticarial vasculitis. Our case characterized itself by postpartumperiod developments which simultaneously show unique distributions of the disease that only limits the lesions to the extremities and sparing abdomen. This pattern of the disease has never been reported, and thus, display the strength of our case report. In conclusion, we report a case of PUPPP in which the lesions developed after labor and were limited to both the legs and arms.

Fig. 1

Multiple itchy erythematous papules and plaques were observed on both the arms and legs. (A) Lesions on the lower extremities. (B, C) Lesions on the upper extremity. Histopathology of the skin lesions. (D) There were mild epidermal spongiosis and perivascular inflammatory cell infiltration (H&E, ×40). (E) At high power magnification, the epidermal focal spongiotic vesicle and perivascular infiltration of many lymphoid cells and few eosinophils were observed (H&E, ×100).

Table 1

Summary of postpartum pruritic urticarial papules and plaques of pregnancy cases

F: female, A: topical corticosteroid, B: oral prednisolone, C: oral antihistamine.