Koro, known as shrinking penis (or testicles, scrotum or vulva in case of a female patient), is a folk illness or culture-bound syndrome specific to some countries in Southeast Asia, once particularly widespread among the Chinese of the south of lower education.
In medicine a culture-specific syndrome is a combination of psychiatric and somatic symptoms that are considered to be a recognizable disease only within a specific society or culture. Some culture-specific syndromes involve somatic symptoms (pain or disturbed function of a body part), while others are purely behavioral. Some example of culture-bond syndrome are the Dhat syndrome in India, the Brain fag syndrome in Africa, the Evil eye between hispanic populations, the susto, etc. The term koro (originally from Indonesia) indicates the shrinkage of the penis or other genital organs, causing eventually the death of the affected person. In the US and Europe, the syndrome is known as genital retraction syndrome.
In China the syndrome is known as shuk yang (suo yang, shuk yang, shook yong, 缩阳). If the patient is a female, the disease will present itself as a form of anxiety about the supposed retraction of the vulva or the nipples. This syndrome was particularly widespread in Southeast Asia; rare are the cases involving persons of non-Han ethnic group. In different cultural environments, such as in Africa, for example, the syndrome has been associated with mass hysteria phenomenon. Sporadic cases of koro among people with non-Southeast-Asian ethnicity have been reported across the globe.
Superstition and traditional Chinese medicine
Traditional Chinese Medicine identifies koro as a sexual disease and ranked it in two categories: cold mix of the liver or yang exhaustion in the kidney. Koro is a mental illness virtually confined to the Chinese people; the origin of the disease has deep roots (it is described during the Qin Dynasty, in the New Collection of remedies of value, 221-207 BC and then by the Eastern Han dynasty physician Zhong Zhang Jing). The book describes the disease as a yin disease of cold qi (the essence) invasion. Alternatively the syndrome is explained as an imbalance of yang mood, sure sign of impending doom.
"The New Collection described this entity with the following characteristics: it followed intercourse, and might have precipitating factor of exposure or ingestion of cold or raw food, it manifested in the male with abdominal pain, retraction of scrotum ot penis and when severe, with spasm and cyanosis of limbs with trismus and death; and in the female with retraction of nipples, abdominal pain with the same dire results." Gwee Ah Leng, Koro - Its origin and nature as a disease entity, 1968
Paradoxically therefore the Traditional Chinese Medicine which describes and seeks to cure the syndrome it is actually the cause, as it is not a real disease, but it is a culture-bound syndrome. According to TCM, the syndrome would also be deadly. For Chinese tradition often the disease is caused by the spirit of a fox. The treatments suggested by MTC are probably worst than the syndrome, both from a psychological and ecological point of view: pray the gods, invoking a Taoist exorcist, drive out the spirit of the fox playing a gong, beating the sick. The ingredients needed for the potion can be herbs, animal penises (eg penis of tiger, deer, seal with everything that goes with it: poaching, illegal wildlife trade, etc), animal horns, etc. Among other treatments DIY there may be manual or mechanical traction of the penis (such as tying the penis to some device); women can pull the nipples or slide metal pins in the nipple to prevent its disappearance.
In recent times Hainan Island and Leizhou Peninsula in Guangdong have been the most affected areas in successive waves (1948, 1955, 1966, 1974, 1984-85, 1987) in conjunction with social tension phenomena, which obviously has suggested the occurrence of the syndrome in coincidence of high stress. The most impressive case happened in Hainan province, in 1984 and it lasted for 5 months. The mass hysteria phenomenon involved dozen of towns: Zhuguo Qin reported that the attack rate was 3,2%, affecting around 2000 to 3000 people, 80% men. A campaign for the prevention of this syndrome was later elaborated: the results have been encouraging since there have not been cases in China. Improvements in economic and social conditions and a better quality of life also contributed to the "vanishing" of the disease.