4 June 2008
We have read with interest the case report by Poulopoulos et al.,1 in which they describe an infant with black hairy tongue. We also encountered a similar case in a 6-year-old female with end-stage renal failure associated with lupus nephritis. The patient developed black tongue, affecting the midline and sparing the sides of the tongue while being treated for peritonitis secondary to peritoneal dialysis. The family admitted that the child has been taking herbal teas of unknown nature.
The patient of Poulopoulos et al. was also consuming renal herbal tea containing chamomile, balsam, mint, fennel, anise and thyme. All of these herbs have antimicrobial properties.2 This may have killed some of the oral bacterial flora leaving the floor for black pigmented bacteria.
We do not know if black tongue is a chance association or a finding in lupus, as there was a similar report of an adult female with lupus.3
Poulopoulos et al. do not mention whether their infant was tested for lupus.