Neisseria meningitidis is a Gram-negative diplococcus which colonises the ciliated mucosa of the nasopharynx and can cause serious infections, such as meningitis and pneumonia, or lead to haematogenous spread.1 Skin manifestations such as petechiae and ecchymosis are also common. However, cellulitis as a manifestation of infection is unusual.
We present the case of a 78-year-old man, with no previous medical history, who consulted with a two-day history of cough and dyspnoea associated with cellulitis in the left lower limb. Blood tests showed 3200 leucocytes/μl (74.5% neutrophils), 78,000 platelets/μl, Hb 11 g/dl, procalcitonin 165 ng/ml, INR 1.5, creatinine 4.92 mg/dl, urea 119 mg/dl, CPK 6000 U/μl and bilirubin 1.4 mg/dl. In Accident and Emergency, the patient found to have multiple-organ dysfunction and so he was admitted to the intensive care unit (ICU). Due to the respiratory symptoms, a PCR for SARS-CoV-2 was performed on nasopharyngeal exudate and was positive. Chest X-ray showed no clear consolidations. Blood cultures were taken and a CT scan of the left lower limb ruled out signs of necrotising fasciitis. Empirical antibiotic therapy for skin and soft tissue infection (SSI) was started with piperacillin-tazobactam, linezolid and clindamycin. On examination at 24 h the leg had worsened, with the appearance of blisters in the area of the cellulitis (Fig. 1). Fluid was sampled from a blister, with biochemical analysis showing pH < 7 and glucose < 10 mg/dl, and sent for culture. The fluid was negative for Streptococcus pyogenes antigen. A multiplex PCR was also performed on this fluid using the FilmArray® Meningitis/Encephalitis (ME) Panel, off-guideline, which detected Neisseria meningitidis, and the culture result of the blister fluid was negative. Twenty-four hours after admission, Neisseria meningitidis was isolated from the blood cultures taken on admission, and antibiotic therapy was de-escalated to ceftriaxone.
In the ICU he required vasoactive support with noradrenaline. After the first 72 h, the patient showed good progress, with improvement of the organic dysfunctions, except for the renal failure, which required haemodialysis sessions. Renal ultrasound and complement study were normal (C3 102 mg/dl, C4 21 mg/dl).
After systemic improvement, the patient's respiratory status worsened in the context of SARS-CoV-2 pneumonia, requiring invasive mechanical ventilation. He received treatment with remdesivir and dexamethasone, progressively correcting the respiratory failure, which allowed extubation after 13 days. The overall evolution was favourable, and he was discharged from the ICU after 37 days and from hospital after a total of 46 days.
Most cases of STIs are caused by beta-haemolytic Streptococcus and Staphylococcus aureus, although in a percentage of cases the causative agent is not known.2,3Neisseria meningitidis is a bacterium sensitive to the antibiotics commonly used in the treatment of cellulitis, and in these infections it is not always easy to obtain a quality sample for culture.1 With this in mind, we suggest that it could be a cause of under-diagnosed cellulitis with negative blood cultures, probably decapitated. To date there are fewer than 20 cases reported in the literature.4,5 In most published cases cellulitis affects the periorbicular region, face and neck.6,7 There are also cases of meningococcal cellulitis in lower limbs, but these are usually patients with risk factors for developing complicated cellulitis.7,8
This patient had no risk factors for invasive meningococcal infection. However, he did have concomitant SARS-CoV-2 infection. Viral infections have been described as a risk factor for invasive meningococcal infection. In fact, there are records of increased severe meningococcal infections in previous viral pandemics, such as the influenza pandemic of 1918–1919.9 In this patient, the respiratory symptoms started two days before the cellulitis and systemic symptoms, so the SARS-CoV-2 infection could have predisposed to meningococcaemia.
In conclusion, we have presented a case of septic shock due to cellulitis, a rare manifestation of Neisseria meningitidis infection, in a patient with concomitant SARS-COV-2 infection as the only known risk factor.
FundingNone.
None.
