[Facial hair in the context of biology]. / Die Gesichtsbehaarung im Kontext der Biologie.

The subject of the variation in facial hair has been somewhat neglected but lies somewhere between dermatology, anthropology and anatomy. Eyelashes, eyebrows, beards, and nose and ear hair show marked ethnic variation. A particular role is played by the variety of kinds of ear hair in Indian and Sinhalese populations.

[Body hair: an atavistic relic?]. / Körperbehaarung: ein atavistisches Relikt?

Hair growth over the entire body is discussed, including the axillary and pubic hair and the hair on the middle phalanges of the fingers, which has special place in the genetic process of hair regression as a whole. Body hair proves to be one of the characteristics that varies markedly with ethnic type.

[Ethnic variations of scalp hair]. / Bemerkungen zur ethnischen Variation des Kopfhaares.

There has been no polytypical variation in human hairforms for at least the last 10,000 years. In view of the wide variety of hair forms, it must be assumed that biological adaptation has occurred. Several features of the scalp hair, such as form, color, thickness, density, maximal length, tensile strength, etc. are clearly genetically determined. When dealing with diseases of the hair, it may be useful for the dermatologist to distinguish between "hair" and "hair".

[Ethnic variation in congenital pigmentation anomalies]. / Ethnische Variation der kongenitalen Pigmentationsanomalien.

Clear ethnic differences are observed in the major form of tyrosinase-negative oculocutaneous albinism as well as in other forms of oculocutaneous albinism, cutaneous albinism and the very rare ocular albinism. Most interesting is the borderline between normal variation and abnormal forms, especially illuminated in rutilism or red headedness in Negroids and high frequencies of pigmentation anomalies without appreciable disadvantages for the carrier, e.g., the reddish skin of geographically isolated Papuans. The very differential frequencies of the occurrence of pigmentation anomalies in some populations are influenced as well by population genetic factors (isolation/inbreeding, founder-effect, heterosis) as also by socio-cultural factors (albinism as a marriage barrier, infanticide), and in some areas perhaps some kind of negative selection in which individuals with the character in question fail to reach reproductive age.

[Eye and hair pigmentation in malignant melanomas and other malignant skin tumors]. / Augen- und Haarpigmentierung beim malignen Melanom und anderen malignen Hauttumoren.

With the intent to determine whether the phenotypic appearance of individuals with skin malignancies could be differentiated from individuals without such tumors, an objective standardized analysis of 183 patients with malignant melanoma and 111 patients with basal cell epithelioma, squamous cell epithelioma and premalignant skin lesions was undertaken. Eye color and hair color were studied in addition to birthplace of the patients. 527 patients without history of tumors were utilized as controls. High risk persons are characterized by light iris colors (for the melanoma group significance of 0.05%, for other tumors significance of 0.001%) and blond or reddish blond hair (for the melanoma group significance of 0.001%). The melanoma patients originated to a greater part from regions north from their present residence (significance of 0.01%) than the group of non-melanoma patients, who originated more often from the vicinity of Maniz (50 degrees N latitude).

[Anthropological aspects of skin color]. / Anthropologische Aspekte der Hautfarbe.

The highly variable spectrum of colors of human skin depends primarily on differences in the activity of the melanocytes and the melanin content, besides other pigments such as carotenoids. In case of a homogenous early-man-color, the following moments may be relevant for the genetic differentiation: primary factors (latitude, climate, radiation), secondary (vegetation, morbific agents) and tertiary (nutritional status, diseases) factors. They modify selection, resulting from population movement, adaptation to new habitats, and temporary isolation. Regarding the protective function of the integument against solar radiation several ways should be considered: hyperpigmentation, additional keratinization, increased deposition of carotenoids, and hypopigmentation.

[Psoriasis and leprosy in the light of common history. A contribution on epidemiology and differential diagnosis]. / Psoriasis und lepra im Schicksal gemeinsamer Geschichte. Ein Beitrag zur Epidemiologie und Differentialdiagnose.

Over the centuries psoriasis was described as a variety of leprosy. It is only in the last century, however, that it was described as a separate entity. Many early medical descriptions of this woridwide affliction can be found, which attempt to distinguish between the various kinds of leprosy. These attempts led to cultural-religious consequences on one hand and to different theories about their contagiousness and curability on the other. Today the current conviction, that with the proof for the existence of a lepra bacillus the question of heritability of the disease can finally be discarded, is being reconsidered. For both psoriasis and leprosy the search for relationships between these diseases and genetically determined markers in the blood-, serum protein- and enzyme-group systems has led to applicable results which, insofar as they can be interpreted as indications of selective factors, will enable us to understand the geographical distribution of both diseases.