On Impedance of the Skin of Leprosy Patients

A Comparative Study between the so-called Normal Skin of the Leprosy Patients and the Normal Skin of Normal Individuals

Abstract

By means of an apparatus specially devised by Dr. Mita, Professor of Physiology of the Iwate Medical University School of Medicine, which is operated with three cps sinusoidal alternating current, the impedance of the following skin of leprosy patients has been investigated: the skin considered to be normal judging from its outer appearance, and obtained from 20 different sites of the whole body in each subject. A total of 173 leprosy patients consisting of 91 males (74 of the lepromatous type and 17 of the tuberculoid type) and 82 females (58 of the lepromatous type and 24 of the tuberculoid type) have been studied. They were all patients hospitalized in the Tohoku Shinsei-en, a national leprosarium located in the Tohoku district of Japan, and the investiga-tion was made in August 1965 under a definite room condition: room temperature 27-29C, and room humidity 74-75%. The sites of the skin examined are as follows being divided largely into two groups and studied statistically because of the special status of the so-called normal skin of the leprosy patients: the first group consisting of the anterior breast, the upper abdomen, the upper part of the back, the lumbar region, and the nape of the neck; the second group consisting of the face (frontal region, cheek, and jaw), the upperarm and forearm (the extensor as well as flexor aspect), the palm and back of the hand, the thigh (the inner as well as outer aspect), the leg (the extensor as well as flexor aspect), and the sole and back of the foot. Comparing the impedance values obtained in the investigations with that of the normal skin of normal individuals examined with the same apparatus in the same season under the same room condition and reported by Dr. Takasu, the following results have been obtained.
I. Results obtained in the first group (the skin of the trunk and the nape of the neck).
(1) The impedance values of the so-called normal skin of the trunk and the nape of the neck of the leprosy patients were both found, as a rule, to be significantly lower than that of the normal skin of normal individuals.
(2) The impedance values of the so-called normal skin of the leprosy patients of the first group were noted not to have any significant age-, sex-, and site-differences.
II. The results obtained in the second group (the face and the extremities).
(1) The impedance values of the face and the upperarm were noted not to be significantly different between the leprosy patients and the normal individuals.
(2) The impedance of the skin of the extremities were noted to have a trend to become higher in values toward the peripheries.
(3) Among the sites of the extremities, the impedance values of the forearm and the hand as well as of the leg and foot were noted to be significantly higher in the leprosy patients than in normal individuals.
(4) As the so-called normal skin of the leprosy patients is occasionally associated with sensible disturbances, the impedance values were also compared between the socalled normal skin with sensible disturbances and the same with no sensible disturbances in the leprosy patients. In the study, the skin of the upperarm and the thigh were investigated, and it was noted in almost all age groups and sites that the impedance values were significantly higher in the skin with sensible disturbances.
Taking the hitherto mentioned results into consideration, the physiological meaning of the impedance of the so-called normal skin of the leprosy patients judged from its outer appearance in summer were surmised as follows.
(1) The impedance value is assumed to be closely related to the sweat function, and also has connection with insensible perspiration as well as blood circulation of the skin.