Meningitis aséptica y anticuerpos anti-β2-glicoproteína-1 en el síndrome de Sweet

Simultaneous presence of nuchal rigidity and skin lesions is suggestive of probable infectious aetiology. However, these signs may also be due to other causes, including drugs, tumours, and such inflammatory diseases as Sweet syndrome. Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is a condition of unknown aetiology that may appear isolated or in association with tumours or inflammatory or autoimmune diseases. Sweet syndrome manifests with skin lesions, systemic symptoms, and occasionally neurological symptoms. We describe the case of a 47-year-old man with no relevant medical history who came to our hospital due to a 2-week history of general discomfort, odynophagia, holocranial headache, bone and muscle pain, and fever; he was treated with amoxicillin and ibuprofen, without success. One week later, he displayed nuchal rigidity and a painful skin eruption on the chest, arms, and legs, in the form of confluent erythematous plaques and nodules. A CSF analysis revealed pleocytosis (73 cells/mm; 100% lymphocytes), high protein levels (0.53 g/L), and normal glucose levels. Bacterial cultures and polymerase chain reaction for herpes virus, enterovirus, Streptococcus, Listeria monocytogenes, and Neisseria meningitidis yielded negative results. A blood analysis revealed an erythrocyte sedimentation rate of 94 mm/h, a C-reactive protein level of 4.82 mg/dL (normal range, ≤0.5 mg/dL), leukocytosis (12 700 leukocytes/mm3, 78% neutrophils), anticardiolipin IgM 21.91 U/mL (normal range, ≤12.5 U/mL), anti2 glycoprotein 1 (B2GP1) IgM 104.51 U/mL (normal range, ≤20 U/mL), and normal levels of tumour markers. A skin biopsy showed neutrophil infiltration in the dermis, and no involvement of blood vessel walls or microthrombosis (Fig. 1). A chest and abdomen CT scan, an MRI study, and a gastroscopy revealed no abnormal findings. No association was found with HLA-Cw1 or HLA-B54. The patient received ceftriaxone plus aciclovir; these drugs were subsequently discontinued due to the absence of bacterial or viral infection. Oral methylprednisolone