Skin biopsy helpful in patients with suspected meningococcal Purpura Fulminans

In the 17-year multicenter retrospective cohort study published in Critical Care, skin biopsy with conventional culture and meningococcal PCR was shown to have a global sensitivity of 88%.

Purpura fulminans is a rare infectious disease having high morbidity and mortality, with 41% deaths in the ICU and 28% of the survivors needing limb amputations with a median number of three amputated limbs. Neisseria meningitidis is the leading responsible bacteria of Purpura Fulminans, accounting for 66% of PF cases.

Skin biopsy is a minimally invasive and simple exam allowing to perform PCR (polymerase chain reaction) and skin culture to detect Neisseria meningitidis. Therefore, Damien Contou and the research team from France aimed to assess skin biopsy sensitivity in adult meningococcal PF patients.

The study included adult patients admitted to the ICU (intensive care unit) for a meningococcal Purpura Fulminans in whom a skin biopsy with conventional and meningococcal PCR was performed.

The study revealed the following findings:

· Among 306 patients admitted for PF, 64% had meningococcal PF, with a skin biopsy performed on 35%.

· Skin biopsy was performed in the median one day after initiating antibiotic therapy.

· In 90% of patients, a standard skin biopsy culture was performed and showed Neisseria meningitidis in 46% of them.

· Neisseria meningitidis PCR on skin biopsy was conducted in 75% of patients and was positive in 98%. Five of these 50 positive meningococcal PCR were performed three days or more after initiating antibiotic therapy.

· Skin biopsy was considered contributive in 88% of patients. The meningococcal serogroup was identified with skin biopsy in 71% of patients.

The study indicates that only 33% of meningococcal PF patients had a skin biopsy conducted. Skin biopsy is contributive in most patients with meningococcal PF, mainly when a meningococcal PCR is performed (up to 3 days following antibiotic therapy initiation).

Skin biopsy with meningococcal PCR and conventional culture has a global sensitivity of 88%.

"Given the PCR's high rentability versus the conventional culture, meningococcal PCR on skin biopsy should be considered in patients with suspected meningococcal PF, even several days after the antibiotic therapy initiation," the researchers concluded.

Reference:

Contou, D., Béduneau, G., Rabault, C. et al. Skin biopsy in adult patients with meningococcal purpura fulminans: a multicenter retrospective cohort study. Crit Care 27, 166 (2023). https://doi.org/10.1186/s13054-023-04461-2