Introduction
Pemphigoid gestationis is a rare dermatological condition, most commonly presented in the second trimester of pregnancy with itching as the key compliant. Since its a common complaint, we tend to miss the diagnosis and treatment at the appropriate time leading to preterm birth and neonatal pemphigoid gestationis.1 Hence this case is being presented to increase the awareness regarding the diagnosis of pemphigoid gestationis in pregnant women with itching.
Case Report
A 29 year old booked primigravida presented to the obstetric department with complaints of itching at 22 weeks which further progressed to hive like rashes over abdomen around umbilicus and later spreading on to arms and thighs within a week, not subsiding with antihistamines. At 24 weeks, patient started having intense itching along with tense fluid filled vesiculobullous lesions for which dermatologist opinion was obtained.
Investigations
In order to confirm the diagnosis Bullous Pemphigoid Antibody titre was done which showed positive at high range (>200U/ml). Following which Skin biopsy and immunoflorescence were done to confirm the diagnosis.
Treatment
Patient was started on Prednisolone 20mg/day at 24weeks and dose was slowly stepped upto 60mg/day. Since patient continued to have new lesions, Azathioprine 100mg/day was added at 28weeks. Following which patient was symptomatically better.
Outcome & follow up
Patient was admitted with preterm premature rupture of membranes at 33wks, progressed spontaneously and delivered a healthy male baby weighing 2.3Kgs. Postnatally baby was completely normal and patient continued to be on tapering doses of steroids and Azathioprine was stopped. Bullous pemphigoid Antibody was repeated which showed a declining trend. As the lesions were severe, postnatal recovery took 6 months.
Discussion
Pemphigoid gestationis is clinically similar to pemphigoid group of autoimmune blistering skin disorders. It occurs in approximately 1 in 50000 pregnancies,2 usually after the second trimester. Women are at high risk of developing graves disease.3 It is an autoimmune response preventing adherence between dermis and epidermis because of different hemidesmosomal proteins. Basement membrane protein 180 is the key structural protein in the placenta which cross reacts with the same protein on the skin producing autoimmune response and complement activation which further leads to deposition of immune complex and chemo attraction of eosinophil granulocytes, leading to tissue damage and blister formation.4 This condition usually starts with intense itchy erythematous papules and plaques around umbilicus then spreads to abdomen, back, chest and extremities, sparing the face, mucosal membranes, palms and soles, later leading to blisters formation.5 Symptoms in early stage resembles pruritic urticarial plaques and papules of pregnancy (PUPP) and Polymorphic Eruptions of Pregnancy(PEP) which lacks both blisters and autoimmune response thus differing from pemphigoid gestationis.6
Classical histopathological findings are urticarial lesions characterised by subepidermal edema with perivascular infiltrate of lymphocytes, histiocytes and eosinophils. The presence of eosinophils is the most constant feature of histopathological appearance of pemphigoid gestationis.7 Direct immunoflorescence demonstrates linear deposition of complement 3(C3) and IgG autoantibodies at the dermoepideral junction.8, 9 Bullous Antibody by ELISA shows circulating IgG antibody against BP180 which correlates with disease severity with sensitivity of 86-97% and specificity of 94-98%.10
Treatment of pemphigoid gestationis starts with topical emollients and antihistamines. In severe cases, systemic steroid therapy and immunosuppresants like Azathioprine, cyclosporine can be used.11 If these treatments are ineffective intravenous immunoglobulin, plasmapheresis and immunoadsorption techniques can be used.12 In a study from UK with 69 patients, 13(19%) were treated with topical corticosteroids, 56(81%) required systemic corticosteroids. Most patients experienced remission with systemic corticosteroids, but 15(22%) required additional treatment with immunosuppressants.13
Generally, this condition tends to exacerbate postpartum in 75% of patients. Duration of active disease ranges from 2weeks to 12 years postpartum.13 Recurrence of disease might happen with women on oral contraceptive pills or during menstruation.14, 15 Recurrence in subsequent pregnancies is almost 90%, occurs early in pregnancy and more severe.16
Fetal concerns
Fetal prognosis is generally good, but risks being small for gestational age babies and premature birth.2 Shornick et al in his observation showed that 16% of patients with Pemphigoid gestationis delivered before 36 weeks, while its 2% in uncomplicated pregnancies.16 Low birth weight babies which is one of the complication is due to the immune response between placental antigens and antibodies leading to placental insufficiency.13 Neonatal pemphigoid occurs due to passive transfer of antibodies from mother to fetus. About 10% of newborns may develop urticarial or vesicular skin lesions. These lesions are self limiting, subsides within few days to weeks when the antibody levels decreases.17 There is no role of induction of labour but needs close monitoring by regular ultrasound in case of low birth weight babies and it is important to be aware of the risks of preterm birth.1
Conclusion
Pemphigoid gestationis is a self limiting condition, needs appropriate diagnosis and treatment. The prognosis is usually good except for the complications like small for gestational age, low birth weight babies and preterm birth. Patients should be counselled regarding the prognosis, treatment possibilities, relapse after delivery and subsequent pregnancies.
