Gram-negative bacterial toe web infection: A survey of 123 cases from the district of Cagliari, Italy

Background. Foot intertrigo is mostly caused by dermatophytes and yeasts, l ess frequently by grampositive and gram-negative bacteria. Nevertheless, th e importance of polymicrobial infections and especially colonizations of Ps eudomonas aeruginosa can cause therapy problems in relation to antibiotic r esistance and the risk of potentially lethal complications. Objective: The aim of this study was to evaluate the main epidemiologic and clinical features of intertrigo from gram-negative bacteria, the function of promoting factors, and the measures taken to treat and prevent this diso rder. Methods: Between 1989 and 1998, 123 cases of intertrigo from gram-negative bacteria were observed at the Cagliari University Dermatology Department. R outine clinical and blood examinations, repeated bacterioscopic and mycolog ic examinations, cultures aimed at identifying the responsible bacteria, an d antibiograms were performed. Results. P aeruginosa was found to be the prevailing pathogen, both alone a nd associated with other gram-negative bacteria (such as Escherichia coli, Proteus mirabilis, Morganella morganii) and grampositive bacteria. Clinical manifestations were similar in the majority of patients: erythema, vesicop ostules, erosions, and marked maceration caused by abundant, malodorous exu date, Lesions affected the interdigital spaces of both feet and frequently extended to the planta and the back of the toes. Patients complained of bur ning and pain. Successful therapies were achieved with combined topical and systemic treatment; to avoid the risk of antimicrobial resistance, the cho ice of the active antibiotic was guided by antibiograms. Conclusion: In all symptomatic toe web infections, the presence of gram-neg ative germs, such as P aeruginosa, should be investigated to avoid the risk of treatment failures and more severe local or systemic complications.