Koro is a culture bound delusional disorder in which individuals have an overpowering belief that their sex organs are retracting and will disappear, despite the lack of any true longstanding changes to the genitals.
[4] The condition can be diagnosed through psychological assessment along with physical examination to rule out genuine disorders of the genitalia that could be causing true retraction.
"Longstanding" refers to changes that are sustained over a significant[specify] period and do not appear reversible, unlike the effect of cold temperatures on some genital regions that cause retraction.
[7] There are cases in which koro symptoms persist for years in a chronic state, indicating a potential co-morbidity with body dysmorphic disorder.
[5] Psychological components of koro anxiety include fear of impending death, penile dissolution and loss of sexual power.
[5][12] Other ideational themes are intra-abdominal organ shrinkage, sex-change to female or eunuch, non-specific physical danger, urinary obstruction, sterility, impending madness, spirit possession and a feeling of being bewitched.
Given that koro is often an “attack” with a great deal of associated anxiety, the physician should ascertain the patient's emotional state along with the timeline from onset to the presentation at the examination.
The manual gives koro's definition as "a term, probably of Malaysian origin, that refers to an episode of sudden and intense anxiety that the penis (or, in females, the vulva and nipples) will recede into the body and possibly cause death.
[5] Traditional Chinese medicine recognises koro as a sexual disease and classifies it into two categories, namely "cold conglomeration in liver" and "depletion of kidney's yang".
Prognosis appears to be better in cases with a previously functional personality, a short history and low frequency of attacks, and a relatively uncomplicated sexual life.
[12] The phenomenon is also found among overseas Chinese in Southeast Asia, especially Malaysia and Indonesia, and less frequently among the Malay and Indonesian inhabitants of the countries.
[32] Sporadic cases of koro among people with non-Southeast-Asian ethnicity have been reported across the globe, for example, Nepali,[33] Sudanese,[34] Jordanian,[35] Tanzanian,[36] Nigerian,[37] French,[38] British,[39][40][41] American[42][43] and Canadian.
[15] Local official records indicate genital retraction epidemics in Hainan Island and Leizhou Peninsula in Guangdong, China, as early as the late nineteenth century.
Newspapers initially reported that some people developed koro after eating the meat of pigs inoculated with a vaccine for swine influenza.
Popular opinion and news media echoed the affected individuals' projection of viewing the epidemic as caused by Vietnamese food and tobacco poisoning in a hideous assault against the Thai people.
Mass Koro epidemic was reported in the state of West Bengal, India from July to December 2010, in the districts near southern part of India-Bangladesh border, affecting hundreds of people.
Locals created some folk managements for this condition like partly submerging the patient in a pond and pulling and holding her nipples or his genital.
Affected individuals in the African outbreaks often interpreted the experience as genital theft, accusing someone with whom they had contact of "stealing" the organ and the spiritual essence, causing impotence.
The perceived motive for theft was associated with local occult belief, the witchcraft of juju, to feed the spiritual agency or to hold the genital for ransom.
[17] Cases were reported in Cotonou, Benin where mobs attacked individuals accused of the penis theft and authorities ordered security forces to curb the violence, following the deaths of five people by vigilantes.
[53] Later reports of outbreak suggest a spread beyond West Africa, including the coverage of episodes in Khartoum, Sudan in September 2003; Banjul, Gambia in October 2003;[17] and Kinshasa, DR Congo in 2008.
[17] A study analyzing the West African epidemics from 1997 to 2003 concluded that rather than psychopathology, the episodes were the product of normal psychological functioning in undisturbed individuals, who were influenced by the local cultural models or social representations.
[3] The Malleus Maleficarum, a fifteenth-century European manual for witchcraft investigations, relates stories of men claiming that their genitals had disappeared, being "hidden by the devil … so that they can be neither seen nor felt."
[55] Witches were said to store the removed genitals in birds' nests or in boxes, where "they move themselves like living members and eat oats and corn".
[13] Factors of cultural expectation in the genesis of koro can be built upon ideas of sex physiology in the traditional Chinese medicine, with free play of imagination which links fatality with genital retraction.
[12] The earliest Western reference to the term koro ("koro-koro") is found in a letter from Celebes (now Sulawesi) by Carl Wilhelm Maurus Schmidtmüller, published in 1849.
[12] The term koro is also known as rok loo (genital shrinkage disease) in Thailand, jinjinnia bemar in Assam, India, and lanuk e laso by the Bogoba tribe in Philippines.