OBJECTIVETo investigate the pathogenic and clinical presentation and laboratory tests of bullous rash in hand, foot and mouth disease (HFMD) in Xi'an from January 2013 to December 2014 by retrospective analysis.

METHODA total of 224 specimens were collected from clinically diagnosed HFMD cases who were characterized by widespread mucocutaneous bullous reactions in Xi'an Children's Hospital from January 2013 to December 2014, the identification and subtyping of the isolates were conducted with real-time fluorescent quantitative RT-PCR. A retrospective analysis was performed to analyze the clinical presentation, laboratory tests and late follow-up problems of the HFMD.

RESULTIn the clinically diagnosed HFMD cases who were characterized by widespread mucocutaneous bullous reactions, 207 were caused by coxsackievirus A6 (CA6), accounting for 92. 4% of all cases with bullous, 4 were caused by enterovirus 71 (EV71), accounting for 1.8%, 10 were caused by coxsackievirus A16 (CA16), accounting for 4. 5%; 4 cases were negative for these viruses. In the cases positive for intestinal virus-nucleic acid, 130 were male, 90 were female; male to female ratio was 1. 44: 1, 203 were <5 years old, accounting for 92. 3%. Leukocytosis was found in 75 cases (34. 1%); high-sensitivity C-reactive protein (hsCRP) increased in 200 cases (90. 9%); elevated myocardial enzyme CK-MB was found in 35 cases (15. 9%), alanine aminotransferase increased in 15 cases (6. 8%); 187 cases had fever (85. 0%). None of the cases had serious complications such as encephalitis or myocarditis. In the course of the critical phase bullous rash or large vesicle-like changes, obvious itching, and facial rash appeared. After the fluid in the bullae was absorbed or the bullae ruptured or became ulcerated, scar formation and large areas of exfoliation occurred, with no effusion on the newly formed epithelium in the base, without significant pigmentation on later follow-up. In the late follow up process, 52 cases in CA6-positive patients (25. 1%) developed onychomadesis within 2-4 weeks after onset, 1 to 8 nails, an average of 4. 3 fell off, new nails grew, the nail bed showed no structural abnormalities and hyperplasia after falling off, the surface was smooth, had no hypertrophy, left no sequelae.

CONCLUSIONThe pathogen in HFMD characterized by widespread bullous reactions was mainly the CA6, this kind of HFMD was mainly mild type, with significant itching, later the bullae may have scar formation and skin exfoliation, in some cases onychomadesis may occur.