Deep skin and soft tissue infection of the neck – fi rst sign of unrecognized diabetes mellitus

Skin and soft tissue infections (SSTIs) are common infectious disorders, while complicated SSTI (cSSTIs) representing the more severe subtype developing deepseated infection, a requirement for surgical intervention, the presence of systemic signs of infection, and the presence of complicating comorbidities [1]. These disorders require initiation of appropriate empiric broad-spectrum antimicrobial therapy, early aggressive surgical intervention for drainage of abscesses and debridement, and identification of responsible bacteria and appropriate de-escalation of antimicrobial therapy [2]. Carbuncles and cSSTIs may be a symptom of unrecognized diabetes mellitus [3].


Sir,
Skin and soft tissue infections (SSTIs) are common infectious disorders, while complicated SSTI (cSSTIs) representing the more severe subtype developing deepseated infection, a requirement for surgical intervention, the presence of systemic signs of infection, and the presence of complicating comorbidities [1]. These disorders require initiation of appropriate empiric broad-spectrum antimicrobial therapy, early aggressive surgical intervention for drainage of abscesses and debridement, and identification of responsible bacteria and appropriate de-escalation of antimicrobial therapy [2]. Carbuncles and cSSTIs may be a symptom of unrecognized diabetes mellitus [3].
A 38 year-old male patient presented with a carbuncle on his neck worsening during 7 days of ambulatory oral antibiosis with ampicillin/sulbactam. His medical history was unremarkable despite a type-I-allergy against and dog and cat epithelia. After a couple of days, he developed fever and malaise. Therefore, he was admitted to the Department of Dermatology and Allergology.
On examination we observed a tense and very painful erythematous swelling on his neck about 10 cm in diameter with central pustulations and putride discharge (Fig. 1). Neck lymph nodes were swollen and painful. Or working diagnosis was cSSTI following a neck carbuncle. Ophthalmologic investigation: Non-proliferative diabetic retinopathy. Treatment: We started with a dose escalation of 3 g ampicillin/sulbactam i.v. and metronidazole 500 mg i.v. every 8 hours and added oral metamizole 3 x 1 g/d. Aggressive surgical drainage of the abscess was performed. The wounds were irrigated repetitively using Ringer's solution, and framycetin sulfate powder was applied. Systemic antibiosis was adapted to microbiological findings, dose was escalated.
Drug therapy of diabetes mellitus was initialized with the diabetologist using a combination of short and long acting insulins: Actrapid HM ® (Novo Nordisk) and Toujeo ® (Insulin Glargin 300 I.E/ml; Sanofi). After release from the hospital the patient was referred to a diabetologist for further treatment and monitoring.
cSSTI are an extreme of the common SSTIs. They often are associated to significant comorbidities, sometimes unrecognized as in the present case. Analysis of comorbidities in patients with deep neck infections demonstrated diabetes mellitus in 19.0% to 20.5% [4,5]. In a meta-analysis of deep neck infections, diabetes mellitus was associated with multispacer spread of infection (Relative risk [RR] 1.96) and complications (RR 2.42) [6].
T h e m o s t c o m m o n b a c t e r i a r e s p o n s i b l e for carbuncles and cSSTI of the neck include anerobic Peptostreptococcus, Streptococcus aureus, Streptococcus viridans, Streptococcus pyogenes, but in diabetics Klebsiella pneumoniae acquires also importance [5,6].
In conclusion, carbuncles and cSSTis can be a symptom of unrecognized and uncontrolled diabetes. Early recognition and a combined approach with aggressive surgery and specific antibiosis is essential to prevent complications such as mediastinitis, pneumonia or sepsis (in case of neck localization). Diabetes and other comorbidities need an adequate treatment in a multidisciplinary approach.

Consent
The examination of the patient was conducted according to the Declaration of Helsinki principles.