os, AKIN LEMONS AND EPILATION ee ee ee The early symptoms of itching and burning of the skin and eves were prohably due mainly te kin irradiation frew the falleet material. However, the chemical nature of this material may have contributed to the irmtation. It has Leen noted (12) that irritating chemicals applied during or shortly after irradiation on- hanre the effects of radiatica. The lack cf prumiinence of an erythema wan wetable, particularly in view of the severity of vnme of the lesions that developed. Wilhelmy (13) states that erythema only occurs when the dove reaching the papillary layer exceeds a cer- ee EE tain level. Perhaps due to the low energy of the beta radiation the dose to the dermis was in- +2 are Ne AP gS GER the lew wrere lesons occurring ele here on the body. it ix kagneal to assume that the feet received a higher done of radiation becaine of proximuty to the growad and thin amy explain the seventy of thew lesions. The longer laten period (desipte higher dene of radiation) may he related to thicknem of the epedermin, cif ferences in length of mitotic evelen or other inherent characterinticn of xkin in diferent areas of the body. The histopatholagical changes noted, such as tleructive and atrophic changes of the epidermix, disturbances in’ keratinization, and atrophy of hair follicles, when taken together are consistent with radiation injury to the skin sufficient to evoke the response. On the other hand, the darkness of the skin and the development of hyperpigmentation may have masked an erythema. Microscopically, a superficial hyperemia was not prominent. Wirth and Raper (10) point out that they were inipressed in their studies on P * radiation of the human skin with the difficulty of distinguishing between true erythema and tanning, particularly in the skin of brunette individuals. It was unfortunate that color filters were not available to aid in distinguishing an erythema us suggested by Harris ¢¢ a/. (14). (9, 12, 17, 18, 19, and 20). Severe injury to the dermis and blood vessels was not observer. The minimal dermal injury with severe epidermal injury is in keeping with the large component of low energy betx material present, re- before development of lesions of the skin is considered to be roughly inversely proportional to the dose of radiation (14, 16). In the present series of cases the relatively long latent pe- trating radiation, but may be more typical of the response to ultra soft roentgen or “Crrenz rays(21). There is no satixfactory explanation for the darker dusky-yray color that appesred in some of the skin lesions as healing progressed. Vascular changes or pigment aberrations might have been responsible. The return to near normalin this prygmentation by 6 months showed the transient nature of this change. The continued absence of pigmentation at the site of the deeper foot lesions at 6 months and 1 vear later sugyests that the pigment-producing elements im these areas were permanently cam, In general, the length of the latent period + ae nod is suggestive of a low dose of radiation. Due to the wide spectrum of beta energies and particulate distribution of radioactive material, strict comparisons cannot be made with previous experience. However, the later development of less severe Jesions in the Ailinginae and Rongerik groups as contrasted with earher deVelopment of more serrous lesions in the Kongelap group isin keeping with a lower skin dose in the former, and a higher skin dose in the latter. tis of interest, however, that the latent period was dependent to some extent on anatomical location. The foot lesions, which were yenerally the most severe lesions encountered, had a longer latent period than tid Fe ln ig RO lla ae RG a meee ay Feereiememe ein aa - = eh sulting in absorption of the greater portion of the energy in the epidermis. Hyperpigmentation of injured areas was a consistent: finding in the Marshallese and the American Negroes. Pigmented lesions were also obverved to a lesser extent in the white Americans. Such pronounced pigmentation ix not characteristic of the usual lesions as de- scribed following exposure to beta or pene- nged. The unique features of the lesions sich as the marked pigmentation, the shsence of obvious Mmultiphasic response. the long latent period,

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