416. The Vasculitic mimic!

Case presentation: A 60 year old gentleman with no comorbidities presented with history of painful blackish discoloration of second and fourth toe of the left foot since a month. He also complained of pain and swelling in both ankles with early morning stiffness lasting for less than an hour. Pain aggravated on activity. He was on diclofenac for pain almost three times a day. He had history of weight loss of 20 kgs in the last two and a half years, part of which was intentional. There was no history of fever, oral ulcers, headache, skin rashes, sinusitis, cough, hemoptysis, tingling and numbness in the body. The patient had past history of admission for abdominal pain and was diagnosed to have malaria. He was not a known case of diabetes, hypertension, dyslipidemia, ischaemic heart disease. There was no history of alcohol consumption, smoking or drug addiction. There was no history of ayurvedic medication intake. No history of drug intake for migraine. On examination all his peripheral pulses were well felt. There was blackish discoloration of his left second and fourth toe (Figure 1). His vitals were normal. Abdominal examination showed mild splenomegaly. Rest of his systemic examination was unremarkable. Diagnostic testing: On evaluation Hemoglobin was 15 g/dl, total WBC count was 22,259 cells/cu mm, Platelets were 9.84 lakh and ESR was 16 mm at end of one hour. Chest x ray, urine examination was normal. There was no proteinuria. ANCA by immunofluoroscence showed 1:10 1+ positive. Anti PR3, Anti MPO were negative. Left lower limb arterial doppler was normal. Serology for HIV, Hepatitis C and HbsAg was negative. His lipid profile, HbA1c was normal. APLA work up was negative. Ultrasound abdomen showed mild splenomegaly. Discussion of the management: In view of leucocytosis ,thrombocytosis, bilateral ankle arthralgia and gangrene we had clinical suspicion of vasculitis etiology and initiated on pulse doses of 500 mg cyclophosphamide once in two weeks, oral steroids at 0.5mg per kg along with aspirin 75mg per day .We followed him up after three doses of cyclophosphamide .There was significant improvement in pain and discolouration of the toes of the left foot but had persistent thrombocytosis (11.89 lakh cells/cu mm) and leucocytosis (23*10 3cells/cu mm) Haematologist opinion was sought who worked up for myeloproliferative neoplasm. He was positive for JAK 2V617H mutation. He was then started on hydroxyurea, aspirin was continued at 75mg per day and steroids was tapered and stopped. Differential and final diagnosis: The initial subacute presentation of the impending gangrene of the toes with well felt peripheral pulses, no comorbidities /addiction, ankle arthralgia, leucocytosis, thrombocytosis, ANCA positivity with initial response to cyclophosphamide lead us to the possible diagnosis of ANCA vasculitis. The past history of malaria a year back would have explained the mild splenomegaly. In view of persistent thrombocytosis post pulse cyclophosphamide therapy possibility of myeloproliferative neoplasm was considered. The work up showed positive for JAK2 V617H mutation. Conclusion: Vasculitis are rare heterogenous disorders with myriad manifestations. It is a diagnostic challenge for the treating physicians. Patients can present with a wide spectrum of manifestations ranging from isolated cutaneous vasculitis to multisystem involvement. It can be mimicked by various diseases of which infections and myeloproliferative diseases are most common. Careful examination, thorough investigations and diligent follow up can help in proper diagnosis. If unrecognised it can lead to untoward consequences. Disclosures: Non