Compared to SLPB patients, MB patients were more likely to be seropositive (adjusted odds ratio (aOR) MB 11.8; 95% CI 7.83-17.8) while PB patients had no difference in risk for seropositivity (aOR PB 1.27; 95% CI 0.86-1.86).
The MB patient group comprised more males, older patients and more patients with a disability grade > 0 than the PB or SLPB groups.
(21,22) We see a similar, but less strong effect in our patient population with regard to the development of PB or MB leprosy: MB patients were less frequently BCG vaccinated than PB and SLPB patients (BCG coverage MB approximately 20%; PB and SLPB, 29%).
Since there was also no serological difference between patients with one or two skin lesions it can be concluded that there is no serological evidence to distinguish between SLPB and PB with 2 lesions, with and without satellite lesions.
The presence of not more than two lesions (regardless of the presence of satellite lesions) and no lesion larger than 10 cm diameter (small sized) may be new criteria for SLPB classification.
From a serological point of view, it seems reasonable to stop counting satellite lesions as whole lesions, to take skin lesion size into account for clinical decision-making, and consider the possibility to include patients with two skin lesions into the SLPB group.