Odor in Pemphigus

A.J. Kanwar, MD, Department of Dermatology, Postgraduate Institute of Medical Education and, Research, Chandigarh 160 012 (India) The experienced internist can diagnose a number of clinical entities by smell alone. The fishy odor of hepatic failure, the ammo-niacal or urinary odor of azotemia and the sweet or fruity odor of diabetic ketoacidosis are well known. On the contrary to the best of our knowledge, dermatologists have only a limited number of disorders at their disposal where smell can be of help. Patients with erythroderma or exfoliative dermatitis tend to have a rancid smell. Over the past few years, we have been struck by a peculiar fishy odor in patients with pemphigus vulgaris and pemphigus foliaceus. More often than not, we find this particular smell to be of great help in making a diagnosis of pemphigus besides Nikolsky’s or Asboe-Hansen’s sign. Whenever there is any doubt, this smell comes to the rescue. It is usual for us to comment that the patient smells like one with pemphigus. The cause of this peculiar odor is not clear to us. It may be due to bacteria which colonize the denuded areas. However, in patients with other cutaneous disorders where colonization and denudation of the skin are prominent features, as for example in toxic epidermal necrolysis or Stevens-Johnson syndrome, this smell is lacking. We would like to share this clinical observation of ours with others in this field. None of the standard textbooks of dermatology make a mention of this particular smell.