Case 1. A 34-year-old Filipino female presented with a three
month history of multiple bilateral tender red nodules
over the distal lower limbs [Fig 1]. She felt well with no
constitutional symptoms, no prior history of preceding infection,
tuberculosis exposure, or animal contact. She had migrated from the
Philippines five years ago. She had no smoking, alcohol or intravenous
drug use. Prior to this episode, she had no significant medical issues,
and was not on any medications or herbal supplements. On examination,
she had tender erythematous subcutaneous nodules on her lower limbs with
angular purpura [Fig 1]. There were bilateral ankle effusions, and
no other synovitis elsewhere. The abdomen was soft and non-tender.
Urinalysis, full blood count, biochemistry and creatinine kinase levels
were normal. Erythrocyte sedimentation rate (ESR) was 44 mm/hr (N
< 20 mm/hr), and C-reactive protein (CRP) 10 mg/dL (N
< 4 mg/dL). Antinuclear antibody, extractable nuclear antigen,
cryoglobulin, cryofibrinogen, rheumatoid factor, anticardiolipin
antibody, β-2 glycoprotein antibody, lupus anticoagulant, antineutrophil
cytoplasmic antibodies, hepatitis B, hepatitis C, HIV, measles, mumps,
and rubella were negative. The interferon gamma release assay was
negative. Incisional biopsy demonstrated fibrinoid necrosis of an
arteriole with a marked perivascular infiltrate composed of lymphocytes,
neutrophils, histiocytes and eosinophils, extending to the subcutis.
Histiocytes were inconspicuous and PUTT and ABPAS staining demonstrates
no pathogens. [Fig 2]. Whole body PET-CT and CT abdominal angiogram
showed no systemic vessel involvement, or end organ ischemia. Prednisone
40mg daily was commenced with normalisation of ESR, CRP, and complete
resolution of subcutaneous nodules after two weeks. Prednisone was
reduced and methotrexate commenced as a steroid-sparing agent.Case 2. A55-year old man was referred with a five month history
of right lower limb ulcer associated with sensory
changes in the lower limb. There were no constitutional symptoms or
other symptoms to suggest systemic disease. Examination demonstrated a
stellate ulcer with retiform purpura [Fig 3] and sensory deficit
along the sural nerve. Physical examination was otherwise unremarkable.
An incisional biopsy demonstrated a prominent lymphohistiocytic
infiltrate of small to medium sized vessels in the deep dermis and
subcutis. A moderate lymphohistiocytic infiltrate was noted within
vessel walls with endarteritis obliterans, degenerate vessel walls and
fibrin thrombi with karyorrhexis in affected lumens. His investigations
showed normal urinalysis, blood count, urea, and electrolytes with no
features of systemic involvement on imaging. Nerve conduction studies
demonstrated isolated right common peroneal neuropathy with no evidence
of a generalised neuropathy or mononeuritis multiplex. The patient was
commenced on a tapering regime of prednisone 60mg daily, methotrexate
15mg weekly and colchicine 0.5 mg tds with resolution of the ulcer over
a period of months. The sensory deficit remained fixed. Follow-up one
year later showed no recurrence of symptoms or signs of vasculitis.