Egg white injury.

A 66-year-old man was admitted to our Department for a sudden loss of consciousness, tonic–clonic movement and psychomotor agitation. During the previous 4 months the patient had complained of drowsiness, fatigue, lack of appetite, and nausea. During the prior 2 months he had experienced hair loss, coating of the tongue, and skin flaking with pruritus. Two hours prior to admission, the patient had experienced loss of spacio-temporal orientation, dizziness, cold sweats, postural instability, and sudden loss of muscle tone in the lower limbs causing a collapse on the ground. On physical examination the skin was dry, greyish, markedly flaky; and the tongue was pale. There was a circumoral dermatitis, as well as a skin rash described as scaly (seborrhoic) and red (eczematous) distributed around the eyes, nose and mouth, along with alopecia and thinning hair. The vital signs were: rate 75 beats/min, blood pressure 145/90 mmHg, and normal respirations. The social history revealed that during the previous year the patient had established a chicken farm, and that each morning, when he had gone to collect the newly laid eggs, he had ingested some of the eggs whose shell was broken. For 3 months, he had eaten daily a mean 6 g of albumen. Laboratory evaluation revealed a minor elevation of the serum cholesterol level. Complete blood count, thyroxine, vitamin B12 and folic acid levels were within reference range. Computerized tomography and magnetic resonance imagining of the brain and spinal cord were normal. No lesions were observed in the temporo-mandibular joint. The audiometric, vestibular and tilt-test examinations, together with electronystagmogram, electroencephalography, electrocardiogram (ECG) and carotid Doppler studies were unrevealing. Additional investigations ruled out infective and autoimmune causes, as well as malignancies. Because of the inability to reach a diagnosis, despite the use of sophisticated technologies, we decided to investigate and review the history of the patient. Much to our surprise, we discovered that at admission, the laboratory determination of biotin was low (98 pmol/L), confirming the diagnosis of egg white injury syndrome (Table 1). Although data are lacking to effectively guide the frequency of follow-up and the specific testing warranted, a reasonable strategy is to follow a patient and re-evaluate him, after biotin supplementation for 1 month, including measurement of biotin status. Our patient was treated with 5 mg 9 3 for 1 month of diathynil neobiotin. Neurologic signs disappeared after 24 h, and the skin lesions after 10 days. The patient has been followed up monthly for 6 months, without clinical and serum alterations. Neurologic and cutaneous manifestations are related to ‘‘egg white injury’’, a cause of biotin deficiency. Biotin (also called vitamin H or coenzyme R) is a watersoluble vitamin of the B complex. ‘‘H’’ is the initial of ‘‘haut’’, the German word for skin, because of the skin involvement in deficiency states [1]. The mechanism by which ingestion of raw egg whites leads to biotin deficiency is the irreversible binding of biotin by avidin, a glyco-protein present in the albumen of raw eggs. The resulting compound renders this vitamin non-absorbable by the human gastro-intestinal tract [2]. Cooking denatures avidin, rendering it susceptible to L. Cammalleri P. Bentivegna M. Malaguarnera (&) Department of Senescence, Urological and Neurological Sciences, University of Catania, Via Messina 829, 95125 Catania, Italy e-mail: [email protected]