Pruritic folliculitis of pregnancy
Gary N. Fox
Pruritic Folliculitis of Pregnancy Pruritic folliculitis of pregnancy may appear any time after the fourth month of gestation. This distinct dermatosis is characterized by pruritus and small, follicle-centered, erythematous papules that may be excoriated or may have the appearance of small pustules. Distribution is variable, although all reported cases have included the abdomen. There is an absence of systemic maternal or fetal toxicity, and the condition resolves spontaneously after delivery. The cause of this dermatosis is unknown. Pruritic folliculitis of pregnancy is a gestational dermatosis characterized by non-bacterial folliculitis. In 1981, Zoberman and Farmer(1) described the condition in six patients; since then, only two other cases have been mentioned in the English literature.(2) The three cases presented in this article provide independent verification that this dermatosis is distinct from the other well-defined pruritic and pustular eruptions of pregnancy. These cases also illustrate that pruritic folliculitis of pregnancy is usually not severe or extensive.
A 24-year-old white woman (gravida 3, para 1, abortus 1) developed a rash at 28 weeks of gestation. Ten days later, she brought the rash to the attention of her physician during a prenatal visit. She was taking no medications except prenatal multivitamins, and she recalled only the usual pigmentary skin changes during her previous pregnancies.
On examination, the patient had multiple erythematous, blanching, follicle-centered papules, 2 to 4 mm in diameter. Some of the papules had a distinct, central pustular component. The eruption was present over the entire abdomen, without predilection for striae or intertriginous areas. The patient complained of moderate pruritus.
Rubella antibody was present, serology was nonreactive and postprandial glucose screening was normal. Ultrasound examination was also normal. Gram staining and culture of a lesion revealed no pathogens.
Sections from a skin biopsy of a representative lesion were examined after staining with hematoxylin-eosin and periodic acid-Schiff (PAS). Neutrophilic infiltration was found in a dilated follicular opening; the infiltration extended to both the overlying surface and the infundibulum. Mild peri-infundibular infiltration and perivascular lymphocytic infiltration were also present. There was no eosinophilic infiltration. No destruction of the follicular wall was evident, and there was no exocytosis, spongiosis, parakeratosis or vesiculation. No microorganisms were seen. Immunofluorescent studies were not thought to be clinically indicated.
Except for the cutaneous eruption, maternal and fetal examinations were normal for gestational age. The patient did not think the cutaneous symptoms were severe enough to warrant treatment. During the ensuing 11 weeks of gestation, there were no changes in symptoms or distribution of lesions. Excoriation was never apparent. Maternal and fetal conditions remained clinically appropriate for gestational age until delivery.
At term, the patient delivered a male infant weighing 3,620 g (7 lb, 15 oz). The Apgar scores at one and five minutes were 7 and 9, respectively. No cutaneous eruption was present in the neonate. The maternal eruption cleared spontaneously within 72 hours of delivery.
A 26-year-old white woman (gravida 3, para 2) in the 27th week of pregnancy noted an extremely pruritic eruption on her abdomen and lateral thighs. Over several weeks, the eruption spread to her arms and legs. The patient’s only medication was prenatal vitamins. She did not remember any symptomatic eruptions during previous pregnancies. Rubella antibody was present, and serology was nonreactive.
The lesions were follicle-centered, erythematous papules, 1 to 3 mm in diameter. Excoriation was evident, and tiny central pustules were visible in the unexcoriated lesions. There was no predilection for abdominal striae, and intertriginous areas were not involved.
Examination of skin biopsy specimens showed folliculitis and perifolliculitis. The follicular wall was partially replaced by an acute fibrinopurulent neutrophilic inflammatory cell infiltrate, with some extravasation of neutrophils into the adjacent dermis. There was an associated superficial perivascular inflammation composed predominantly of lymphocytes and histiocytes with some intermixed neutrophils. No fungal or bacterial organisms were identified.
Incomplete relief of pruritus was provided by topical triamcinolone cream, 0.1 percent. Maternal and fetal examinations, including ultrasonography, remained clinically appropriate for gestational age. The eruption persisted until 41 weeks of gestation, when the patient delivered a normal female infant weighing 3,260 g (7 lb, 3 oz). The infant’s Apgar scores were 7 at one minute and 9 at five minutes. The maternal skin eruption resolved completely within several days of delivery.
A 38-year-old white woman (gravida 4, para 2, abortus 1) underwent genetic amniocentesis at 16 weeks of gestation, with normal results. She developed idiopathic hydramnios at 27 weeks of gestation. Rubella antibody was present, serology was nonreactive and postprandial glucose screening was normal. Obstetric ultrasound was remarkable only for the hydramnios.
At 34 weeks of gestation, small, mildly pruritic, follicle-centered, minimally purulent, erythematous papules developed on the patient’s legs. The patient denied symptomatic eruptions with previous pregnancies, and her only medication was prenatal vitamins. About two weeks later, lesions appeared on the abdomen, without predilection for the striae. The patient declined biopsy. Fluocinonide cream, 0.05 percent, relieved the pruritus but did not alter the appearance of the eruption.
At 38 weeks of gestation, the patient delivered a male infant weighing 4,480 g (9 lb, 14 oz), with no apparent anomalies. The Apgar scores at one and five minutes were 7 and 9, respectively. The maternal rash disappeared suddenly in the puerperium.
Only one study(1) specifically addressing pruritic folliculitis of pregnancy was found in the English literature. It appears, however, that this condition is clinically distinct from the other well-defined pruritic and pustular dermatoses of pregnancy, specifically pruritic urticarial papules and plaques of pregnancy (PUPPP), impetigo herpetiformis and herpes gestationis.
Pruritic folliculitis of pregnancy has the following characteristic features: (1) mild to severe pruritus; (2) small, follicle-centered, erythematous papules, which may be excoriated or may have the appearance of small pustules; (3) onset at any time after the fourth month of gestation; (4) variable distribution, ranging from abdominal involvement to generalized eruption, with all cases reported to date eventually involving the abdomen; (5) a histopathology resembling that of acute folliculitis; (6) absence of systemic maternal or fetal toxicity, and (7) spontaneous resolution, usually by one month postpartum. In two of the reported cases, multiparous women recalled eruptions with previous pregnancies. Direct immunofluorescent microscopy was performed in four patients and was negative for deposition of IgG, IgM, IgA and C3 complement.(1)
Unlike pruritic folliculitis of pregnancy, PUPPP typically has a marked urticarial component with prominent involvement of the striae gravidarum. PUPPP characteristically occurs in primigravidas and generally does not recur in subsequent pregnancies. Like pruritic folliculitis, PUPPP does not cause fetal compromise. Histologically, PUPPP is characterized by a nondiagnostic, dermal, perivascular lymphohistiocytic infiltration, which may be accompanied by epidermal changes.(3,4)
Impetigo herpetiformis is a rare gestational eruption that typically begins in intertriginous areas as irregular patches of erythema with superficial pustules at the margins. Patients generally feel and appear ill. Since maternal and fetal death can result, recognition of this condition is important. Histologically, impetigo herpetiformis resembles pustular psoriasis.(5)
Herpes gestationis often begins with a viral-like prodrome followed by a pruritic, urticarial eruption on the abdomen. Initially, the eruption may resemble that seen in PUPPP. Within a few days, however, vesicles and tense bullae usually develop. Clinically, herpes gestationis may resemble erythema multiforme or dermatitis herpetiformis.(5) Depending on whether a bullous or urticarial lesion is biopsied, the histology may be similar to that bullous pemphigoid or erythema multiforme.(6) Direct immunofluorescence usually demonstrates C3 deposition along the basement membrane. Pathologically, this condition closely resembles bullous pemphigoid. An IgG herpes gestationis factor has been isolated, and the newborn may exhibit a transient eruption due to transplacental acquisition of this factor.(6,7)
Etiology, Pathogenesis and Incidence
The etiology and pathogenesis of pruritic folliculitis of pregnancy are unknown. No information on serum or urinary hormone levels has been reported. No immuneassociated phenomena have been identified, and no hematologic, gastrointestinal or other abnormalities have been reported.
The incidence of pruritic folliculitis of pregnancy is also unknown. PUPPP, which may be the most common pruritic eruption of pregnancy, was described by Lawley and colleagues(3) in 1979. They attributed the previous absence of reports of PUPPP to misdiagnosis, the occurrence of the eruption late in pregnancy and spontaneous remission shortly after delivery; in addition, individual dermatologists probably saw such a small number of cases that the entity was not described. Pruritic folliculitis of pregnancy may also be more common than is currently recognized, and for the same reasons. Furthermore, this dermatitis may be minimally symptomatic, limited in distribution and much less dramatic in appearance than PUPPP. Hence, it may attract even less attention than PUPPP.
The cases reported in this article were identified at different times over the course of approximately one year (August, January and April deliveries). The patients were unknown to each other and therefore would be unlikely to represent an epidemic experience with a rare entity. Rather, pruritic folliculitis of pregnancy may be more common than is generally thought. Although large-scale studies are needed to accurately establish the incidence of this disorder, our three patients were identified among approximately 250 obstetric patients who delivered over a nine-month period.
Treatment and Prognosis
Empiric therapies have included topical corticosteroids, lindane (Kwell, Scabene), systemic hydroxyzine (Atarax, Atozine, Durrax) and diphenhydramine (Benadryl). Relief of mild pruritus has been reported without objective improvement in the eruption.(1)
There is no evidence of compromised maternal or fetal well-being in the reported cases of pruritic folliculitis of pregnancy. In all cases in which follow-up has been obtained, the dermatosis has been self-limited. For the safety of the patient, it is important to differentiate pruritic folliculitis of pregnancy from the more serious eruptions that may occur during pregnancy.
PHOTO : Pruritic folliculitis of pregnancy. (Left) Discrete, scattered, follicle-centered,
PHOTO : erythematous papules and pustules on the abdomen of the patient in Case 1. (Right) Closer
PHOTO : view of the abdomen, demonstrating the pustular component of the eruption.
PHOTO : Lesions of pruritic folliculitis of pregnancy on the leg of the patient in Case 3. REFERENCES (1)Zoberman E, Farmer ER. Pruritic folliculitis of pregnancy. Arch Dermatol 1981;117:20-2. (2)Holmes RC, Black MM. The specific dermatoses of pregnancy. J Am Acad Dermatol 1983;8:405-12. (3)Lawley TJ, Hertz KC, Wade TR, Ackerman AB, Katz SI. Pruritic urticarial papules and plaques of pregnancy. JAMA 1979;241:1696-9. (4)Yancey KB, Hall RP, Lawley TJ. Pruritic urticarial papules and plaques of pregnancy. Clinical experience in twenty-five patients. J Am Acad Dermatol 1984;10:473-80. (5)Winton GB, Lewis CW. Dermatoses of pregnancy. J Am Acad Dermatol 1982;6:977-98. (6)Sasseville D, Wilkinson RD, Schnader JY. Dermatoses of pregnancy. Int J Dermatol 1981;20:223-41. (7)Callen JP. Pregnancy’s effects on the skin. Common and uncommon changes. Postgrad Med 1984;75(8):138-45.
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