Pseudomonas Mastitis Caused by Hot Tub Exposure

Abstract

To the Editors: Mastitis most frequently occurs in relation to lactation, whereas nonlactational mastitis is rare in adolescents.1 We report a case of an 11-year-old prepubertal girl presenting with mastitis caused by Pseudomonas aeruginosa after using a hot tub. The patient presented to hospital with a 3-day history of left-sided mastalgia and breast swelling. Twenty-four hours after onset, she developed a widespread pustular, erythematous rash affecting her trunk, groin area, thighs, and upper arms, but sparing her face and neck. It first appeared on her abdomen in a single area, and then became widespread over a 24-hour period. She had no systemic symptoms. Four days before presenting to the hospital, she had shared a hot tub with several other people at a friend's house. Several children and one adult also noted a similar rash, but no one developed mastalgia or mastitis. Breast examination demonstrated a tender left breast, with overlying mild erythema. She had associated tender lymphadenopathy in the left axilla. There were no signs of a breast abscess. She also had a widespread symmetrical papulopustular rash affecting her trunk, groins, upper thighs, and upper arms. The pustules varied in size, but were not larger than 4 mm in diameter. The rash was not itchy, but several of the pustules were tender. A blood sample was obtained for assessment of a full blood count, urea and electrolytes, and C-reactive protein level. A swab was obtained from a pustule for microscopy, culture and sensitivity. The blood test results were within normal range, except for a slightly elevated C-reactive protein level of 11 mg/L (normal range, 0–10 mg/L). She was treated with oral flucloxacillin and regular analgesia for the mastitis. Clinical review after 48 hours revealed no improvement in her symptoms. A dermatology opinion was sought for the rash, and a literature search revealed an association between Pseudomonas folliculitis, the suspected clinical diagnosis for the rash, and mastitis. The results of the swab culture, reported on that day, identified P. aeruginosa. The antibiotic was changed to oral ciprofloxacin, as per sensitivity, and 24 hours later the rash had improved dramatically. There was complete resolution of the Pseudomonas folliculitis after 1 week. The mastitis had improved greatly, but there was still some mild tenderness, which settled after a few days. A swab obtained from a pustule of the patient's younger brother also identified P. aeruginosa. The other children who developed a rash did not attend hospital, and their symptoms resolved spontaneously within a few days. The association of mastitis with Pseudomonas folliculitis does not appear to be well recognized among clinicians treating either condition. In our patient, it is probable that the mastitis occurred as a direct result of infection of the mammary gland or glands of Montgomery.2,3 Her breasts were enlarging because of the influence of pubertal hormones, increasing their susceptibility to infection,4 and the high bather load and occlusion of her swimming costume made her susceptible to the development of infection with Pseudomonas.2,5 Susannah M. C. George, MRCP Department of Dermatology Brighton and Sussex University Hospitals NHS Trust Jaspal Rattan, MRCGP Department of Paediatrics Western Sussex Hospitals NHS Trust Katy Walker, MRCPCH Department of Paediatrics Brighton and Sussex University Hospitals NHS Trust Brighton, United Kingdom Anil Garg, FRCPCH, FRCPI Department of Paediatrics Western Sussex Hospitals NHS Trust Worthing, United Kingdom