Eosinophilic fasciitis following postpartum: A rare case report

Abstract

Eosinophilic fasciitis is a rare connective tissue disease characterized by increased levels of peripheral blood eosinophils and infiltration in the myofascia. The diagnosis of eosinophilic fasciitis is primarily based on clinical manifestations, laboratory tests, and pathological biopsy, with the exclusion of other possible causes of fasciitis and eosinophil increase. Herein, we report a case of postnatal eosinophilic fasciitis occurring in a woman in her 20s, who developed the condition in her right forearm. The patient, who was postpartum, showed considerable recovery after conservative treatment with the corticosteroid prednisone.

Background

Eosinophilic fasciitis (EF) is a rare connective tissue disease with unclear etiology. ¹ Its main clinical manifestations include symmetrical skin sclerosis of the extremities; swelling and pain, with or without rash; and itching. Laboratory examinations have shown peripheral blood eosinophilia, hypergammaglobulinemia, and an accelerated erythrocyte sedimentation rate (ESR) in patients with EF. ² Magnetic resonance imaging (MRI) has shown isointensity or slight hypointensity in the superficial fascia of the limbs, deep fascia, and myofascia on extensive fat-suppressed (FS) T1-weighted imaging (WI) as well as hyperintensity on FS T2-WI and FS proton density–weighted imaging (PDWI). In the progressive stage of the lesion, a patchy edema signal around the thickened deep fascia is observed. ³ Several diagnostic criteria have been proposed^4,5 (including two major and five minor criteria, Table 1). Diagnosis can be made by fulfilling two major criteria or one major criterion plus two minor criteria.

Table 1.

Proposed criteria for the diagnosis of patients with eosinophilic fasciitis.

Major criteria

1. Swelling, induration, and thickening of the skin and subcutaneous tissue that is symmetrical or nonsymmetrical, diffuse (extremities, trunk, and abdomen) or localized (extremities)

2. Fascial thickening with accumulation of lymphocytes and macrophages with or without eosinophilic infiltration (determined by full-thickness wedge biopsy of clinically affected skin)

Minor criteria

1. Eosinophilia >0.5 × 109/L

2. Hypergammaglobulinemia >1.5 g/L

3. Muscle weakness and/or elevated aldolase levels

4. Groove sign and/or peau d'orange

5. Hyperintense fascia on magnetic resonance T2-weighted images

Exclusion criteria: diagnosis of systemic sclerosis

Case report

A woman in her 20s was admitted to the outpatient department of Quzhou People’s Hospital in June 2024 due to joint soreness in the wrist and elbow joints that had persisted for more than 3 months following a vaginal delivery. The delivery was uncomplicated, and this was her first pregnancy. No significant complications were observed during the delivery process. She had no known history of autoimmune diseases or other relevant medical conditions. Muscle strength assessment revealed mild weakness, particularly in the right upper limb. Laboratory investigations conducted post-admission revealed a sustained acceleration of ESR (34–63 mm/h), accompanied with elevated levels of peripheral blood eosinophils (absolute value: 1.48 × 10⁹/L, 20%). MRI revealed no discernible abnormalities in the signal from the right forearm musculature. Instead, it showed homogeneous thickening of the superficial and deep subcutaneous and myofascial fascia, with isointensity or slight hypointensity on FS T1-WI (Figure 1(a)) and hyperintensity on FS T2-WI and FS-PDWI (Figure 1(b) and (c)). Furthermore, homogeneous enhancement was observed following enhancement scanning (Figure 1(d)-(f)). The presence of a groove sign on the skin (Figure 1(g)), a characteristic feature of EF, was noted. Subsequent skin biopsy (Figure 2) revealed the presence of subcutaneous granulomatous tissue, fibrous tissue hyperplasia, lymphoplasmacytic infiltration, and small eosinophilic infiltration. These findings, when considered alongside the abovementioned clinical features, led to the confirmation of the diagnosis of EF. After obtaining the patient’s consent, she was treated with the glucocorticoid prednisone at a dose of 40 mg per day for 1 week and was discharged from the hospital after improvement. No further hospital visits were made for the follow-up.

Figure 1.

Magnetic resonance imaging (MRI) demonstrated that the signal of the right forearm muscle exhibited no discernible abnormality. Additionally, the subcutaneous superficial and deep fascia and myofascia displayed uniform thickening with (a) isointensity or slight hypointensity on FS T1-WI; (b, c) hyperintensity on FS T2-WI; and (d, e, and f) homogeneous enhancement in the enhanced scans and (g) Groove sign (arrows).

Figure 2.

Pathology findings. Histopathological examination showed a perivascular and interstitial inflammatory infiltrate of lymphocytes and eosinophils in the deep reticular dermis and subcutis (hematoxylin and eosin staining, 200×).

The reporting of this study conforms to the Case Report (CARE) guidelines. ⁶ Written informed consent was obtained from the patient for publication of anonymized data. The study received an ethical exemption from the Ethics Committee of Quzhou People’s Hospital (No. 2024-119).

Discussion

EF was initially documented by Shulman ⁷ ; hence, it is also referred to as Shulman’s syndrome. EF is predominantly idiopathic and possibly linked to strenuous physical exertion, trauma (including physical or psychological), infectious diseases, autoimmune disorders, chemicals, drugs, infections, heredity, radiation, and physical factors. A small proportion of patients (5%–10%) developed malignant tumors, which were predominantly associated with hematological malignancies. ⁸ To the best of our knowledge, this case represents the first report of EF occurring immediately following delivery, suggesting that delivery is a potential but underrecognized risk factor for this condition.

Patients with EF are typically aged between 20 and 60 years, with no obvious sex difference, and the disease presents with an acute or subacute onset. The clinical manifestations of this condition include progressive and symmetrical limb edema, stiffness, pain, and limitation of movement. In a few cases, the trunk or neck may be affected, whereas joint contracture may occur in severe cases. Some patients also present with muscle weakness, myalgia, and arthralgia. The typical signs of EF include a “groove” sign, which presents as a depressed image along the veins and is most apparent when the limb is elevated. ⁹ This groove sign was evident in the current case.

MRI is the preferred method for diagnosing EF, with FS T1-WI demonstrating thickening of the fascia with a hyperintensity on FS T2-WI. Significant enhancement of the thickened fascia could be observed on intensified scanning. The thickness of the fascia, intensity of the FS T2-WI signal, and extent of enhancement were positively correlated with the degree of disease activity. ¹⁰

A comprehensive biopsy of the affected skin, fascia, and muscle is essential for establishing the diagnosis of EF, in accordance with the proposed criteria. Histological examination revealed the presence of lymphocytes, macrophages, plasma cells, and eosinophils within the myofascia under a light microscope. In the early stages of the disease, eosinophilic infiltration is observed. The affected fascia is characterized by thickening and firm adherence to the skeletal muscle, whereas the dermis and epidermis typically demonstrate no abnormalities. ⁵

Glucocorticoids represent the primary treatment option for EF, whereas immunosuppressive therapy may be considered for patients with steroid-refractory or glucocorticoid-resistant EF. Intravenous immunoglobulin, monoclonal anti-infliximab antibodies, and photochemotherapy are also effective. ¹¹ EF is a self-limiting disease with a good prognosis, and poor prognosis has rarely been reported. ¹²

While differentiating EF from other inflammatory systemic diseases, systemic sclerosis (SSc) is the most relevant disease. SSc is characterized by skin thickening and fibrosis, primarily affecting subcutaneous tissue rather than fascia. Unlike EF, SSc often involves multiple organs, including the lungs, gastrointestinal tract, kidneys, and heart. Raynaud’s phenomenon is common in SSc but absent in EF. Additionally, EF lesions do not affect the face or fingers, unlike SSc. Autoantibody testing plays a crucial role in differentiation. Patients with SSc often test positive for antinuclear antibodies (ANA) and specific extractable nuclear antigen (ENA) autoantibodies, such as anti-Scl70 and anti-centromere antibodies, which suggest SSc. ¹³ In contrast, EF does not typically involve autoantibody positivity. In this case, ANA and ENA tests were performed, which returned negative, aiding in ruling out SSc. Notably, high-dose glucocorticoid therapy in undiagnosed patients with SSc can cause renal crisis due to acute kidney injury. However, with negative ANA and ENA tests, this risk is not a concern for the current patient. MRI remains a valuable tool for differentiation, clearly showing fascia involvement in EF, which is typically absent in SSc. Histopathological examinations are also crucial. SSc is characterized by dermal and subcutaneous fibrosis with atrophic epidermis, whereas EF shows eosinophilic infiltration and fascial thickening without significant dermal or epidermal changes.

In summary, there are no standardized diagnostic criteria for EF, whose diagnosis mainly relies on clinical manifestations, laboratory tests, MRI, and pathological biopsy. FS T1-WI indicates thickening of the affected fascia, and FS T2-WI indicates swelling and signal increase in the deep fascia. MRI could assess the scope of EF lesions and provide a reference basis for accurate localization of biopsy sites, identification of other diseases, and evaluation of treatment efficacy, which should be further explored in clinical practice.