Footnotes

• AB and GR contributed equally.

• Contributors AB, GR and FF wrote the manuscript. EMD, chief of Dermatology department, contributed to the final diagnosis and approved the final draft of the manuscript. AMB, chief of Pathological Anatomy department, was very helpful for the histology. RC, chief of Rheumatology department, approved the final draft of the manuscript. MdM, chief of Pediatric Medicine department, approved the final draft of the manuscript.

• Competing interests None declared.

• Patient consent Obtained.

• Provenance and peer review Not commissioned; internally peer reviewed.