Bullous Striae Distensae: Three Cases, One Common Thread

Dear Editor, Striae distensae (SD), commonly known as stretch marks, are a prevalent form of dermal scarring associated with various physiological conditions such as growth spurt, rapid weight gain or loss, pregnancy, and with iatrogenic causes such as prolonged topical or systemic corticosteroid usage. SD most commonly appears on the lower back, buttocks, thighs, calves, abdomen, and breasts.[1] Steroid-induced striae appear to be broader and larger than physiological striae.[2] Secondary changes within SD, including fluid accumulation, urticaria, ulceration, emphysema, and dehiscence, have been reported previously.[3] Bullous striae distensae develop as a result of fluid accumulation within existing SD in patients with anasarca. Herein, we report three cases of bullous striae distensae: one in a 38-week primigravida with bullae within physiological striae, and two in patients with nephrotic syndrome with bullae within steroid-induced striae. Case 1 A 5-year-old girl, a known case of nephrotic syndrome with anasarca, presented with multiple fluid-filled lesions on the abdomen for the past week. She was on fluctuating doses of oral prednisolone for 3 years and had a Cushingoid body habitus and a moon facies. The striae on the flanks and lower abdomen demonstrated clear fluid-filled bullae along their distribution, as seen in Figure 1a and b. Laboratory investigations revealed low serum albumin levels, elevated 24-hour urine protein, and a high urine protein-to-creatinine ratio. A diagnosis of bullous SD was made and was referred for protein correction and diuresis.Figure 1: Multiple bullous striae distensae on (a) right and (b) left abdominal flanks, with noticeable ascitesCase 2 A 23-year-old male with anasarca was referred for gradual fluid accumulation within pre-existing striae on the abdomen and thighs for the past month. He had been diagnosed with adult-onset nephrotic syndrome four years ago and was put on varying doses of oral prednisolone since then. Multiple, well-defined, clear fluid-filled bullae arranged linearly on the striae and multiple atrophic striae were noted on the abdominal flanks and bilateral medial thighs [Figure 2a-d]. Laboratory investigation showed low serum albumin and low protein levels. Elevated 24-hour urine protein was detected. A diagnosis of bullous SD was made, and the patient was advised protein correction and diuresis.Figure 2: Multiple bullous striae distensae noted on (a) right (b) left abdominal flanks, and on medial aspects of (c) right and (d) left thighCase 3 A 21-year-old primigravida at 38 weeks of gestation presented with asymptomatic fluid accumulation within striae gravidarum for the past month. A few striae showed crusting and ulcerations [Figure 3]. She had pitting edema on the abdomen and feet, with a blood pressure of 110/70 mmHg. Laboratory tests revealed hypoalbuminemia and low total protein levels, while urine routine and 24-hour urine protein were normal. Aspiration from the bullae yielded clear, straw-colored serous fluid that was acellular and had a low protein content (0.20 g%), consistent with a transudate. A biopsy was advised to rule out pemphigoid gestationis, but was deferred due to lack of consent. However, the diagnosis was considered unlikely given the confinement of lesions to striae, absence of pruritus, mucosal involvement, and systemic symptoms. The lesions resolved with correction of protein levels, without systemic therapy, supporting a non-autoimmune etiology.Figure 3: Bullous striae gravidarum on lower abdomen noted among few crusted and ulcerated striaeBullous SD is a rare condition characterized by fluid accumulation within pre-existing striae, most commonly seen in patients receiving moderate to high doses of corticosteroids over prolonged periods.[3] It is often associated with hypoalbuminemia or generalized edema, suggesting a synergistic effect of steroid-induced dermal atrophy and protein deficiency. Glucocorticoids reduce the tensile strength of the dermis by increasing collagen breakdown. Striae show significant reduction in fibrillin and elastin fibers, and increased glycosaminoglycans, which are hydrophilic.[2,4] Reduced albumin levels lower the oncotic pressure, allowing fluid from the intravascular space to move out, resulting in edema.[3] This edema fluid accumulates preferentially within the striae due to their higher content of glycosaminoglycans and lowered tensile strength.[2] A rare variant—yellow bullous striae distensae—has been described in a patient with liver dysfunction, where hypoalbuminemia and elevated bilirubin levels contributed to yellow discoloration of the edema fluid.[5] Based on our observations, we conclude that generalized edema in patients with either physiological or pathological striae can lead to the development of bullous SD. All three cases demonstrated hypoalbuminemia as a contributing factor. One patient developed bullae within striae gravidarum, while the other two—both on long-term corticosteroid therapy for nephrotic syndrome—developed bullae within steroid-induced SD. In these latter cases, earlier initiation of steroid-sparing agents might have minimized the need for prolonged corticosteroid use and potentially prevented the development of bullous striae. Dermatologists and physicians need to be aware of this rather benign entity to avoid unnecessary interventions. Diagnosis and correction of protein and fluid imbalances typically reverse the condition, leading to resolution of the bullous changes. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Use of artificial intelligence (AI) The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.