Background: Each myositis-specific autoantibody (MSA) tends to have a distinct clinical presentation. Coexistence of MSAs do not commonly occur. If they do, it is unknown if there is an overlap of clinical features or prognostic implications. There are a few reported cases of overlap between these antibodies, mostly reported in patients with Japanese descent. Our aim for this case report is to turn more attention and interest for future MSA profile studies in the Hispanic population, which may hopefully spur better therapies if we realize the prognostic implications of certain myositis subsets including double-positive autoantibody syndromes. Case presentation: A 27-year-old Hispanic female was admitted to the medical intensive care unit due to acute hypoxemic respiratory failure secondary to acute respiratory distress syndrome (ARDS). She had failed conventional mechanical ventilation and was cannulated for venovenous extracorporeal membrane oxygenation (VV-ECMO) to manage her respiratory failure. She had erythematous scaly plaques on bilateral 3rd metacarpophalangeal joints on examination. Her autoimmune workup revealed positivity for both anti-PL-7(threonyl) and anti-melanoma differentiation-associated gene 5 (MDA5) autoantibodies. After extensive evaluation, it was concluded that she had rapidly progressive interstitial lung disease (RPILD) due to amyopathic dermatomyositis. Despite maximal medical management, she was ultimately transitioned to comfort care measures and expired. Conclusion: We would like to highlight the rarity of double antibody positive amyopathic dermatomyositis. This unique clinical presentation has only been reported in persons of Japanese descent. Our case is likely to be the first reported to occur in a person of Hispanic descent in the United States. The rarity of our case could stimulate further study of overlapping MSA to understand its varied presentations and prognoses including possible tendency toward a rapidly progressive ILD phenotype. Earlier detection of these clinical syndromes can lead to better outcomes for patients with RPILD. This case report could also herald an increased recognition and understanding of MSA profile in the Hispanic population in the USA.

A 31-year-old woman with a history of bilateral carpal tunnel surgery complained of worsening hand pains and swelling. Subsequently, she presented for rheumatologic evaluation with generalized arthralgias, symmetric polyarthritis of the hands and feet, shiny skin with tightness and thickening, tender periungual erythema, malar rash, and photosensitivity. The only laboratory abnormality found then was a positive antinuclear antibody. Her joint symptoms were responsive to low-dose prednisone and hydroxychloroquine. However, the skin tightness progressed proximally and centrally and developed around the mouth. At that point, more specific autoimmune work-up showed negative relevant antibodies, and repeat antinuclear antibody tests turned out negative. Later, she reported dysphagia and hoarseness, and ecchymotic rashes appeared on the face and forearm. Biopsy of the forearm lesion showed leukocytoclastic vasculitis. Staining for amyloid was negative. Subsequently, she was found to have hypogammaglobulinemia and Bence-Jones proteinuria; the progression of her skin symptoms provoked a repeat skin biopsy with special stains that demonstrated amyloidosis. Bone marrow biopsy showed >75% plasma cells, skeletal survey revealed multiple lytic lesions, and a diagnosis of multiple myeloma with associated amyloidosis was made. Despite the initial features of connective tissue disease in this young woman, a steadfast workup revealed the source of her problem.

We report a patient with antineutrophilic cytoplasmic antibody (ANCA) vasculitis that was preceded by witnessed black widow spider bites. The patient initially presented with a diffuse painful skin rash that developed after a few hours post bite. He was treated initially with topical ointment for the suspected bite. However, subsequently a few days later the patient returned to the hospital with similar, but more progressive rash with haemoptysis and acute hypoxic respiratory failure requiring supplemental oxygen. Immunology work up showed elevated titre of peri-nuclear ANCA. Bronchoscopy revealed diffuse alveolar haemorrhage. The patient was treated successfully with methylprednisolone and rituximab.