Recurrent Temporal Infections: The Link to Systemic Lupus Erythematosus

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multisystem microvascular inflammation with the generation of numerous autoantibodies, particularly the anti-double-stranded DNA antibody and anti-ribonucleic acid antibody (autoantibodies to the ribonucleoprotein, which represent Ro, La, Sm, RNP, Scl-70 and Jo1) [1–3].

The first symptoms of SLE are fatigue and cutaneous and musculoskeletal symptoms [4–9]. On the face, the classical features include generalized maculopapular rash and annular or psoriasiform cutaneous eruption [3].

SLE affects the immune system and predisposes patients to many types of infections. The most common infections involve the respiratory tract, urinary tract, and skin [10]. Infection of the facial skin and the surrounding musculoskeletal area is reported infrequently [11]. While diffuse myalgia is reported by up to 50% of patients with SLE, conditions such as inflammatory myositis are rarely observed [12]. The literature describes that the most commonly reported sites for myositis are the lower limbs [13]. Other possible musculoskeletal pathological conditions detectable in SLE include osteomyelitis [14].

In a recent systematic review including data from 23 countries, including Malaysia, the prevalence and incidence of SLE were shown to be from 3.2 to 159 per 100 000 and 0.3 to 8.7 per 100 000 persons, respectively [15].

While the literature on the prevalence and incidence of SLE are plenty, the opposite was observed in the literature of the incidence and prevalence of osteomyelitis among patients with SLE. A population-based study in Taiwan showed that the incidence rate of osteomyelitis for men with SLE was 255.02 per 100 000 person-years and for women with SLE, 164.41 per 100 000 person-years. When compared with the control group (osteomyelitis patients without SLE), the incidence rate ratio was 8.52 (95% confidence interval (CI) 7.24–10.05) [16].

Treatment of SLE differs based on the severity of the disease. For mild to moderate disease, treatment often involves antimalarial drugs, glucocorticosteroids, and non-steroidal anti-inflammatory drugs (for arthritis and serositis) and often immunosuppressive therapy for treating persistent disease activity and decreasing glucocorticosteroids use [17]. For patients with severe SLE, immunosuppressive therapy is often initiated alongside the glucocorticosteroids and other drugs, particularly for lupus nephritis [17].

The objective of this case report was to describe the clinical course of pyomyositis and osteomyelitis of the face in a middle-aged Malay woman.

Case Report

IMAGING:

A CT scan (TOSHIBA Aquilion One, Toshiba Medical Systems Co., Ltd, Japan) of the head with contrast was performed initially to rule out bony infection. CT showed focal thickening of the fascia adjacent to the left temporalis muscle (Figure 2). The temporalis muscle and both globes were normal, with no extraconal or intraconal lesions observed. The initial impression was a solid periosteal reaction of the zygoma secondary to chronic congestion, possibly from the previous trauma episode.

MRI (Siemens MRI 3.0 Tesla Verio, Germany) was performed when the initial incision and drainage provided was not successful. The intention was to evaluate the soft tissue adjacent to the zygomatic bone, as well as the bone marrow. Figure 3 shows the axial MR images in (Figure 3A) T1-weighted sequence, (Figure 3B) fat-suppressed post-gadolinium sequence, (Figure 3C) fat-suppressed T2-weighted sequence, and (Figure 3D) subsequent follow-up MRI (during SLE treatment) in T2-weighted sequence.

The findings of MRI included fatty marrow replacement within the left zygomatic bone, prominent periosteal reaction surrounding the left zygomatic bone, and swollen left temporalis muscle and fascia. The findings were suggestive of residual osteomyelitis changes within the left zygomatic bone, with surrounding myositis of the left temporalis muscle.

INCISIONAL BIOPSY:

Since the initial incision and drainage and antibiotic therapy did not resolve the swelling features, which remained similar to the past 9 months (Figure 4), an exploration and incisional biopsy under general anesthesia was performed. Intraoperatively, the left zygomatic body and frontal bone were identified, without any bony perforation or cavitation. Granulation tissue with a sinus tract was observed in the periosteal layer. No pus was observed during the biopsy. The biopsy samples were collected from (1) granulation tissue and (2) bone, including the periosteum and marrow.

The histopathological results from the specimens were not specified. The results showed an area of fibrosis interspersed with some lobules of adipocytes. The tissue was heavily infiltrated by chronic inflammatory cells, lymphocytes, histiocytes, and eosinophils. This description was in accordance with chronic inflammation with granulation tissue formation.

LABORATORY BLOOD TESTS:

Apart from the routine blood tests, we performed other blood investigations to rule out autoimmune disease. This was performed following the patient’s report of the dry eyes and dry mouth, as well as the unresolved infection issue. The antinu-clear antibodies, complement 3 and 4, anti-double stranded DNA (anti-dsDNA), extractable nuclear antigen, and rheumatoid factor were investigated alongside the full blood count, renal profile, liver function test, fasting blood glucose, C-reactive protein, and alkaline phosphatase. Urine full examination microscopy examination and urine protein creatinine index were also performed.

The renal profile and fasting blood glucose results were unre-markable. The total protein was slightly raised, at 85 g/L (reference range: 64–83 g/L). The urine full examination microscopy examination and urine protein creatinine index were normal. The results of the immunologic investigation are shown in Table 1. The antinuclear antibodies result was positive, with 1/640 titer, a high titer that indicated high susceptibility for autoimmune diseases. In addition, the titer for the anti-dsDNA was 352.98 IU/mL, indicating the disease was in an active phase. High anti-dsDNA is especially exhibited in patients with musculoskeletal involvement [18].

The positivity of the SSA/Ro60 alone indicated the diagnosis of Sjogren syndrome with the association of SLE [19]. The full blood count results showed chronic mild anemia with hypochromic features and neutropenia and lymphopenia, which are common hematological features in SLE (Table 2).

TREATMENT:

Following the immunological blood investigation, we referred this patient to the SLE team for further treatment. The SLE team confirmed the diagnosis of SLE with Sjogren syndrome. She was referred to the ophthalmology team, and both teams co-managed her condition. She was started on 200 mg oral hydrochloroquine once daily and 5 mg oral prednisolone, also once daily. The ophthalmology team prescribed eye drops for the dryness.

Following a 6-month review, another MRI was performed. The post-treatment MRI showed remarkable improvement, compared with the initial imaging (Figure 3D). The left temporalis muscle and fascia were back to normal size. The surrounding subcutaneous fat was no longer streaky. The periosteal reaction of the adjacent left zygomatic bone remained, but to a lesser degree. The left extraconal inflammatory lesions were significantly reduced in size.

At present, she is continuing the medical treatment of 200 mg oral hydrochloroquine and 5 mg oral prednisolone, both taken once daily, and the eye drops.

Discussion

SIGNIFICANCE:

The significance of myositis in SLE in this patient has yet to be observed. At the time of this writing, this patient remained healthy without any morbidity. It has been shown that myositis in SLE responds well to corticosteroids. This patient is closely monitored for SLE-myositis overlap syndrome, as this could lead to poor prognosis, especially when there is evidence of pulmonary involvement [41].

LIMITATIONS:

One of the most important investigations that could have been performed is a muscle biopsy to confirm the diagnosis of myositis. Following that, immunohistochemical and immunopathological analyses would be performed on the muscle to ascertain the most accurate myositis type [42]. We performed an incisional biopsy of the affected site, and the histopathological examination reported non-specific chronic inflammation.

We did not specify the muscle examination, as myositis was not in our differential diagnoses at that time.

In addition, during the first presentation, a microbiology examination of the pus revealed normal flora. More investigation should be conducted to confirm whether it was aseptic osteomyelitis or whether the bacteria had been eliminated from previous antibiotic treatment.

Conclusions

Chronic facial musculoskeletal infection, such as myositis and osteomyelitis, must be investigated thoroughly in patients with SLE to determine whether the condition is explicitly related to infection or to the disease itself.