Pulmonary embolism as the primary presentation of IgA vasculitis

Background

IgA vasculitis (Henoch-Schonlein purpura (HSP)) is a small vessel vasculitis that presents predominantly in the paediatric population and far less common in adults. Thrombotic complications are uncommon in IgA vasculitis, and a few cases have been reported in the literature about coagulation abnormalities, especially in the adult population. Pillebout et al 1 analysed 250 adults with IgA vasculitis; none of them presented with thrombotic complications. Moreover, Li et al 2 conducted a literature review on eight patients with IgA vasculitis who had associated thrombotic complications; pulmonary embolism was not reported. On review of the literature and Medline search, this is the first case describing pulmonary embolism related to IgA vasculitis in an adult patient.

Case presentation

A 47-year-old man with a medical history of type II diabetes mellitus and hypertension presented to the hospital with sudden onset of shortness of breath. He also mentioned that 1 week ago, he noticed swelling of his right leg and a painful erythematous skin rash on both lower limbs.

A review of systems was positive for mild non-specific diffuse abdominal pain of the same duration. He denied smoking, alcohol drinking or illegal drug use. He mentioned that he drinks 3 L of water daily and is physically active at baseline. On physical examination, he was hypotensive with blood pressure 82/40, tachycardiac, tachypneic with a respiratory rate of 35 breaths/min and oxygen saturation 82% on room air. The physical examination showed clear lung sounds. The abdomen was soft, not distended with diffuse tenderness to palpation. Extremities showed reddish to purple, non-blanchable, tender purpuric lesions on both legs and, to a lesser extent, on the right forearm (figure 1).

Investigations

Labs were remarkable for white cell count of 16.0×10⁹/L, platelets 268×10⁹/L, haemoglobin 146 g/L, troponin 95 pg/mL, B-natriuretic peptide 195 pg/mL, C reactive protein 9.4 mg/dL and creatinine 0.84 mg/dL. The international normalised ratio was 1.0 and activated partial thromboplastin time 23 seconds. Antinuclear antibodies (ANA), antidouble-stranded DNA, antineutrophil cytoplasmic antibodies (ANCAs) and hepatitis panels were negative. The ECG showed sinus tachycardia. Bedside echocardiogram showed an ejection fraction of 50%–55%, with moderately dilated right ventricle and mobile echo density noted in the proximal right pulmonary artery consistent with possible pulmonary embolism. Subsequently, CT angiogram (CTA) of the chest showed a large saddle embolus with extensive bilateral pulmonary emboli more marked on the right side (figure 2).

Further workup included an ultrasound of both lower limbs, which showed extensive deep venous thrombosis of the right venous system from the right femoral vein down to the calf venous sinuses. CT of the abdomen also showed mild thickening of the cecum and proximal ascending colon suspicious for mild non-specific colitis. Due to non-thrombocytopenic purpura, with abdominal pain, we had a clinical suspicion of vasculitis. After evaluation by a dermatopathologist, a punch skin biopsy was obtained from the lesions in the right distal posterior upper arm. Direct immunofluorescence study findings showed immune deposits of IgA and C3 in blood vessel walls consistent with an immune complex vasculitis, IgA type (HSP).

Differential diagnosis

Our differential diagnosis for this adult male who presented with acute dyspnoea and hypoxia included the exclusion of cardiac causes such as myocardial infarction, arrhythmias and pulmonary embolism. The diagnosis of pulmonary embolism was achieved based on the specific echocardiogram and CTA findings. Moreover, the skin rash that started 1 week prior raised our suspicion about the correlation between the rash and the pulmonary embolism. We excluded other causes of purpura based on the normal platelet count and coagulation profile. Additionally, the normal ANA, ANCA and hepatitis markers ruled out other causes of vasculitis. The presence of abdominal pain and non-thrombocytopenic purpura in children would make IgA vasculitis on the top of the differential list. However, our patient was an adult without renal disease or arthralgia, which made the diagnosis more challenging. Eventually, we decided to proceed with the skin biopsy to solve the dilemma, that was consistent with the diagnosis of IgA vasculitis.

Treatment

Due to the haemodynamic instability at the time of admission and the presence of right ventricular strain, the patient was given thrombolytic therapy (alteplase), was started on a heparin drip and admitted to the intensive care unit. After 48 hours, the patient was switched to rivaroxaban 15 mg two times per day for 21 days, followed by 20 mg once daily for long term anticoagulation. Due to the presence of abdominal pain, purpuric skin rash and absence of renal involvement, we decided to give a short course of steroids 40 mg for 1 week, then 20 mg for another week and slowly tapered over the course of 2 weeks.

Outcome and follow-up

The patient was discharged home and was instructed to follow-up with a haematologist or his primary care physician for hereditary and acquired thrombophilia workup after completion of the anticoagulation course. By the time of discharge, he reported the resolution of his abdominal pain and slight improvement of his skin lesions. As this was an unprovoked pulmonary embolism in an adult male with a large clot burden, he will likely need indefinite anticoagulation.