Prurigo pigmentosa treated with Jessner’s peel and irradiation with an 830‐nm light‐emitting diode

caused by an inflammatory reaction triggered by infectious agents. Indeed, infection-related cases of PLC have been described after viral (Epstein–Barr virus, HIV, cytomegalovirus, Varicella zoster virus, Parvovirus B 19), bacteria (Staphylococcus, Streptococcus, Mycoplasma) or parasitic (Toxoplasma gondii) infections. Also, resolution of PLC after tonsillectomy in a patient with chronic tonsillitis was reported. Lastly, in a retrospective study of 124 patients, Ersoy-Evans et al. found a prior history of infection before onset of skin lesions in 30% of the cases. We report here an intriguing case of PLC after MMR vaccination. So far, there is no reported case of PL either after MMR infection questioning the role of the vaccine itself. The main cutaneous side-effects after MMR vaccine include a skin rash 7–11 days after injection that lasts several days. To the best of our knowledge, only one case of vaccination-related PL has been reported thus far. Torinuki described the case of a 2.5-year-old girl who developed an acute form of PL 5 days after the injection of a freeze-dried live attenuated measles vaccine. In our case, eruption occurred 10 days after vaccination and evolved over several months as a chronic variant of PL. Such chronic evolution is compatible with the ‘‘natural history’’ of PL chronica, as its median duration is usually around 20 months. Ersoy-Evans et al. administrated p.o. erythromycin estolate or ethylsuccinate to 80% of their affected children and two-thirds of these displayed at least a partial response with a median response time of 2 months. As our patient was seen 4 months after onset of PL, it remains difficult to assess whether resolution of PL was related to erythromycin or to the natural course of the disease. Moreover, we cannot rule out that another infection occurred spontaneously prior or during vaccination and went unnoticed.