Yellow dermatology: Highlighting its diagnostic and teaching challenge

Abstract

Objective There are many skin diseases that might present as yellowish skin lesions initially or during the course of the disease. The objective of the study is to record all patients that have yellowish rash during the progress of the disease and according to daily clinical practice and their importance in dermatology and general medicine.   Methods All patients that had yellowish skin rash during the course of the disease were enrolled during the period from February 2014 to March 2021.They were well-assessed and classified. Clinical photographs with some histopathological findings were recorded.   Results The following diseases were classified to have yellow skin rash initially or during the course of the disease and their frequencies were calculated, in addition to the medical importance to patients and dermatologists: 1- Histiocytosis- xanthogranuloma group. 2- Xanthoma groups. 3-Xanthomatous morphea. 4- Keratoderma. 5- Calcinosis cutis. 6- Systemic sclerosis. 7-Pseudoxanthoma elasticum. 8- Papular mucinosis. 9- Necrobiosis lipoidica. 10-Xanthomastocytoma. 11- Yellow nail syndrome. 12- Ecchymosis. 13-Nevus sebaceous. 14-Sebaceous hyperplasia. 15-Nevus anemicus. 16-Yellow teeth. In addition, anemia and jaundice usually present as generalized yellowish skin discoloration.   Conclusion Yellow dermatology is a group of diseases that characteristically presents with yellowish skin lesions initially or during the progression of the disease. They are well classified to be informative in medical practice and teaching sessions. The cause of this color is different according to the disease status as could be fat deposition, fat engulfing cells, connective tissue degeneration, sebaceous cells hyperplasia, hemoglobin and hemosiderin deposition, vasoconstriction, or unknown reason.