Itchy, blistering rash in pregnancy: pemphigoid gestationis

Abstract

Pemphigoid gestationis is a rare autoimmune blistering disorder associated with pregnancy that may present diagnostic challenges, particularly when onset occurs postpartum. We describe a woman in her 30s who developed an intensely pruritic blistering eruption 1 day after delivery. Histopathology was nondiscriminatory, but direct immunofluorescence demonstrated specific findings—including linear complement deposition along the basement membrane—confirming the diagnosis. This case highlights a practical diagnostic approach to postpartum blistering eruptions and underscores the importance of immunofluorescence studies and neonatal monitoring.

KEY POINTS

• Pemphigoid gestationis may present postpartum and mimic other dermatoses in pregnancy, infection, or allergic dermatoses.

• Blistering eruptions in pregnant or postpartum patients warrant evaluation for autoimmune blistering disease.

• Both routine histopathology and direct immunofluorescence should be considered in the diagnostic workup of suspected cases.

• Neonates should be examined for transient blistering due to transplacental antibody transfer.

• Treatment for both mother and baby should be patient-centered and closely coordinated with a multidisciplinary team.

CME

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Dates for credit claim: September 1, 2026, to September 1, 2027.

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CME

CME Information: https://ce.bswhealth.com/BUMC_Proceedings_CME_info

Credit Claim Process: To claim CME for this activity, read the entire article and go to ce.bswhealth.com/2026BUMC_Proceedings_Sep_PG. You will register for the course, pay any relevant fee, take the quiz, complete the evaluation, and claim your CME credit.

Dates for credit claim: September 1, 2026, to September 1, 2027.

For questions about CME credit, visit our website ce.bswhealth.com/contact-us.

CASE SUMMARY

A woman in her 30s, gravida 6, para 6, developed an intensely pruritic vesiculobullous rash 1 day postpartum for which dermatology was consulted. Her recent pregnancy was complicated by gestational hypertension (on nifedipine) and preterm premature rupture of membranes requiring cesarean section. She had no history of rashes in childhood, adulthood, or past pregnancies, no complications during prior pregnancies, and no history of diabetes, thyroid dysfunction, autoimmune diseases, or bleeding or clotting disorders.

The rash was first noted on her abdomen with subsequent spread to her trunk and bilateral upper and lower extremities. She endorsed the development of blistering within affected areas but denied mucosal lesions. She denied recent travel, sick contacts (including exposure to viral illnesses such as varicella), and a history of cold sores.

Physical examination exhibited crusted and excoriated erosions along with pink, edematous papules and small plaques, many with overlying vesicles and bullae scattered on the trunk, chest, bilateral upper and lower extremities, and palms and soles (Figure 1a). There was no involvement of conjunctiva, mouth, or genitals. Two punch biopsies from the left thigh were obtained for hematoxylin and eosin (H&E) staining and direct immunofluorescence (DIF) (Figure 1b). Histopathology demonstrated spongiotic dermatitis with eosinophilic spongiosis and marked papillary dermal edema without viral cytopathic change. DIF revealed extensive linear deposition of complement component C3 along the basement membrane zone (Figure 1c), confirming the diagnosis of pemphigoid gestationis.

Figure 1.

(a) Scattered crusted and excoriated erosions, pink edematous papules, and clear vesicles noted on bilateral lower extremities. (b) Localization of DIF and H&E biopsy sites. (c) DIF study exhibiting extensive linear C3 at the basement membrane.

The patient received topical corticosteroids and oral prednisone (starting at a dose of 1 mg/kg) with clearance. Given this excellent clinical response, a taper was initiated and completed over the following 4 weeks without recurrence. Her baby did not develop any cutaneous or mucosal lesions.

CLINICAL QUESTIONS

1. A 35-year-old woman, gravida 1, para 0, presents to your clinic with a new onset of blistering rash. She denies any history of autoimmune, dermatologic, or rheumatologic disease. Infectious workup is largely negative. Which of the following diagnostic studies is often most specific for pemphigoid gestationis when assessed early in the disease course?

   1. Serum antinuclear antibody testing

   2. Skin biopsy for H&E

   3. Skin biopsy for DIF

   4. Viral polymerase chain reaction testing

2. Which potential complication should be specifically assessed in neonates born to mothers with pemphigoid gestationis?

   1. Congenital limb anomalies

   2. Neonatal blistering due to transplacental antibody transfer

   3. Severe neonatal hypoglycemia

   4. Congenital heart disease

Answers are provided at the end of the article.

DISCUSSION

Pemphigoid gestationis is a rare pregnancy-associated autoimmune subepidermal blistering disorder caused by autoantibodies directed against hemidesmosomal proteins, most commonly BP180.¹ Disease onset typically occurs during the second or third trimester; however, postpartum presentation occurs in a minority of cases and may lead to diagnostic delay or misdiagnosis.^2–6

Patients typically present with intensely pruritic urticarial papules and plaques that classically progress to vesicles and bullae. Pemphigoid gestationis lesions frequently start on the abdomen with involvement of the periumbilical region and then subsequently spread to the trunk and extremities; the face and mucous membranes are usually spared.^1,3,6 Postpartum onset may raise concern for infectious, allergic, or drug-related etiologies. Routine histopathology, a skin biopsy that illustrates what is happening in the skin on a cellular level, may demonstrate eosinophilic spongiosis, dermal edema, and separation along the basement membrane zone, although it can be nonspecific, particularly early in the disease course. DIF, a skin biopsy that highlights deposition of autoantibodies in different layers of the skin, is integral to diagnosis and characteristically reveals linear complement C3 deposition at the dermoepidermal junction, distinguishing pemphigoid gestationis from other pregnancy-associated dermatoses. Additional diagnostic tools include specific serum enzyme-linked immunoassays (ELISA), a blood test that detects serum levels of maternal IgG Ab against NC16A (extracellular domain of BP180), and the C4d immunochemistry technique, which assesses C4d deposition at the dermoepidermal junction. Serum testing is particularly useful when biopsies are nondiagnostic or inconclusive but suspicion remains high or to assess treatment response. High titers of anti-BP180 antibody by ELISA have also been shown to correlate with adverse pregnancy outcomes.^1,3,5–7

The goal of therapy is to relieve pruritus and prevent blister formation.³ Mild disease may be managed with topical corticosteroids and antihistamines, while more extensive disease often requires systemic agents (which may include systemic corticosteroids, cyclosporine, dupilumab, and/or intravenous immunoglobulin, among others). Treatment decisions should consider postpartum status, breastfeeding plans, and disease severity.^1,3,6,8–10 Multidisciplinary collaboration among dermatology, obstetrics, and internal medicine is necessary.

It is important to note that affected mothers experience an elevated risk for and should be monitored for other autoimmune conditions such as Graves’ disease, Hashimoto’s thyroiditis, autoimmune thrombocytopenia, pernicious anemia, vitiligo, ulcerative colitis, and alopecia areata.^1,5,8,9 Additionally, approximately 10% of women will experience recurrence of lesions with menstruation or oral contraceptive use, and pemphigoid gestationis is estimated to recur in approximately 50% to 70% of subsequent pregnancies.³

Given that pathogenic IgG antibodies can cross the placenta, neonates born to affected mothers should be examined for transient blistering eruptions, which typically resolve spontaneously.^2,4 Overall, maternal and neonatal prognoses are favorable with appropriate diagnosis and management.^1,3,6,8–10

ANSWERS TO CLINICAL QUESTIONS

Question 1, c. DIF is often the most specific study early in the course of pemphigoid gestationis. It demonstrates linear deposition of complement C3 along the dermoepidermal junction and distinguishes pemphigoid gestationis from polymorphic eruption of pregnancy and other mimickers, which have negative DIF findings. Routine histopathology alone may be nondiagnostic/nondiscriminatory early in the disease.^1,3,5–7

Question 2, b. Maternal IgG autoantibodies can cross the placenta and cause transient blistering in approximately 10% to 13% of neonates born to mothers with pemphigoid gestationis. These lesions are usually self-limited, but recognition is important to avoid unnecessary infectious evaluations and to provide symptom-directed treatment and reassurance to caregivers.^1,3,6,8–10

DISCLOSURE STATEMENT

The authors report no funding or conflicts of interest.