<i>Desiderosmia</i> (olfactory craving): A novel symptom associated with iron deficiency anemia
Authors: Bryar R. Hansen, Wayne A. Bottner, Aishwarya Ravindran, Ramona DeJesus, Ronald S. Go
Journal: American Journal of Hematology (2017)

Patients with iron deficiency anemia (IDA) may develop a compulsive craving and purposive consumption of substances that the individual does not define as food, a condition known as pica.1 The hypothesis that such behavior may ameliorate iron deficiency is not substantiated, since most pica substances do not have much bioavailable iron.1, 2 Experience from our practices (unpublished) and others3 suggest that the cravings may not necessarily be for consumption of the pica substances, but rather a desire for their taste, a sensation of the presence in the mouth, or sensation produced by mastication. To our knowledge, non-oro-gustatory craving in the setting of IDA has not been previously described. In this study, we will describe 3 patients with IDA who presented with olfactory cravings. The first case was a 49-year old woman who sought medical consultation because of a 2-month history of a compulsion to smell the odor of charcoal. After barbecuing, her family would put charcoal in their backyard. She could not resist the scent and would go out several times a week to pick up and smell the charcoal. This craving was especially strong after raining, during which the odor of charcoal would be more intense. She denied eating the charcoal. Because she also complained of dizziness, laboratory tests were performed, which led to the diagnosis of IDA (hemoglobin of 7.4 g/dL [normal, 12-15.5]; ferritin 2 µg/L [normal, 11-307]). The cause of IDA was determined to be menorrhagia. She took oral iron supplementation with resolution of IDA. During her 3 month follow-up visit, she reported that her olfactory craving had disappeared. Ten years later, her symptoms have not recurred. We report 2 other cases with similar presentation and clinical course. The salient findings of all 3 cases are summarized in Table 1. We report a novel olfactory craving symptom associated with IDA. All 3 patients presented with such symptom, albeit attraction toward odors from different substances. A similar olfactory phenomenon was previously reported over a decade ago in a survey of 300 pregnant women by Nancy Rumsey Cooksey, RN, a very astute certified childbirth educator. In her study, 40 patients described smelling one or more substances, the most common of which were pine oil cleaning solutions and gasoline. However, the women were neither tested nor treated for iron deficiency and their outcomes were not reported. Interestingly, 20% of the women also had concurrent pica.3 The effects of IDA on the olfactory system have only been minimally explored. In an animal study, iron-deficient rats had prolonged exploratory time (sniffing) for attractive odorants compared to controls. The hypothesis was that IDA would decrease the activity of these enzymes resulting in a net reduction of inhibitory olfactory inputs.4 Another study compared the olfactory function of IDA patients with healthy subjects and found a heightened sensitivity (lower threshold) in detecting odorant among patients with IDA.5 These reports support an association between the physiological changes in olfaction and iron store. These findings and our patient experience provide suggestive evidence that an olfactory craving symptom, entirely separate from pica, exists in certain patients suffering from IDA or during pregnancy. For this, we propose the term, desiderosmia, derived from the Latin word "desiderare" for desire and the Greek word "osme" for smell. Also, 'de-sidero' indicates a reduction in iron, which relates to iron deficiency. In naming this relatively unexplored symptom associated with iron deficiency anemia or pregnancy, we hope to shed light on this condition, and hopefully inspire further investigation. Additionally, providing a definite name may lead to a more specific classification and less misunderstanding of this peculiar symptom overall. The authors declare that they have no conflicts of interest with the content of this article.