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. Koro is also known as shrinking penis, and was listed in the Diagnostic and Statistical Manual of Mental Disorders.
The syndrome occurs worldwide, and mass hysteria of genital-shrinkage anxiety has a history in Africa, Asia and Europe. In the United States and Europe, the syndrome is commonly known as genital retraction syndrome.
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.
The word was borrowed from Malay and means the head of a turtle (or tortoise), referring to how it looks when they retract their heads into their shells.
Signs and symptoms
Most patients report acute anxiety attacks due to perceived genital retraction and/or genital shrinkage, despite a lack of any objectively visible biological changes in the genitalia that are longstanding. "Longstanding" refers to changes that are sustained over a significant period of time and do not appear reversible, unlike the effect of cold temperatures on some genital regions that cause retraction. These changes may trigger a koro attack when observed, although the effects of cold temperatures are objectively reversible. According to literature, episodes usually last several hours, though the duration may be as long as two days. There are cases in which koro symptoms persist for years in a chronic state, indicating a potential co-morbidity with body dysmorphic disorder. In addition to retraction, other symptoms include a perception of alteration of penis shape and loss of penile muscle tone. In cases when patients have no perception of retraction, some patients may complain of genital paraesthesia or genital shortening. Among females, the cardinal symptom is nipple retraction in the breast, generally into the breast as a whole. Similarly, a woman may be seen grabbing her own breast, pulling her nipple, or even having iron pins inserted into the nipple.
Causes
Psychosexual conflicts, personality factors, and cultural beliefs are considered as being of etiological significance to koro.
Diagnosis
Several criteria are typically used to make a diagnosis of koro. The primary criterion is a patient's report of genital (typically penile or female nipple) retraction despite a lack of objective physical evidence demonstrating retraction. This is accompanied by severe anxiety related to the retraction, fear of death as a result of retraction, and use of mechanical means to prevent retraction. Cases that do not meet all the requirements are generally classified as koro-like symptoms or given a diagnosis of partial koro syndrome.
A physical examination should involve an assessment of overall health along with a detailed genital examination. In men, genital examination should be performed immediately after penile exposure, to avoid changes due to external temperature. The primary intent of the male exam is to exclude genuine penile anomalies such as hypospadias, epispadias and Peyronie's disease. Careful measurements of flaccid length, stretched length and flaccid girth will also be useful. If male patients insist that their penis is shrinking and disappearing, Attempts have been made by numerous authors to place koro into different classes. For example, koro may fit into the group of "specific culture-imposed nosophobia" (classification with cardinal sign), "the genital retraction taxon" (classification with common factors between syndromes), and the group with "culture-related beliefs as causes for the occurrence" (classification according to how the syndromes might be affected by cultural factors).
Various authors have attempted to distinguish between complete and incomplete forms of koro, along with cultural and non-cultural forms. Cultural forms are said to involve a cultural belief or myth which plays a role in the genesis and spread of the disease in the community. These are regarded as complete forms of koro, matching all the symptoms required for diagnosis without significant co-morbidity.
Differential diagnosis
Men who present with this complaint may have koro, but they may also be misinformed about normal genital size. Penile dysmorphophobia is related to body dysmorphic disorder (BDD), defined by the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (Text Revision) (DSM-IV-TR) as a condition marked by excessive preoccupation with an imaginary or minor defect in a facial feature or localized part of the body. BDD is different from koro. In koro, a patient is overcome with the belief that his penis is actively shrinking, and it may be in imminent danger of disappearing. Clinical literature indicates that these two psychological conditions should be separated during differential diagnosis. For example, one physical disorder that causes loss of penile size is Peyronie's disease, where the tunica albuginea develops scar tissue that prevents the full expansion of an erection and causes flaccid penis retraction. Additionally, a buried penis is a normally developed penis, partially covered by the suprapubic fat which can be surgically removed.
Indigenous treatment
In China, traditional treatment based on the causes suggested by cultural beliefs are administered to the patient. Praying to gods and asking Taoist priests to perform exorcism is common. If a fox spirit is believed to be involved, people may hit gongs or beat the person to drive it out. The person will receive a yang- or yin-augmenting Chinese medicine to try to balance the internal conditions, usually including herbs, pilose antler (stag of deer) or deer tail, and tiger penis, deer penis, or fur seal penis. Other medicinal foods for therapy are pepper soup, ginger soup and liquor.
Sporadic cases of koro among people with non-Southeast-Asian ethnicity have been reported across the globe, for example, Nepali, Sudanese, Jordanian, Tanzanian, Nigerian, French, British, American and Canadian. In most of the non-Chinese cases in the Western Hemisphere, fear of genital shrinkage is reported but not all the other typical koro symptoms, such as fear of death, as in endemic countries. The incomplete forms of koro are regarded as the non-cultural forms, while the complete form with acute anxiety is the classical culture-bound type.
An epidemic outbreak in November 1976 in Isan, Thailand caused at least 350 cases, most of them Thai and males. 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. Another large-scale epidemic in Thailand occurred in 1982.
Mass Koro epidemic was reported in Labour Camps in Kochi, Kerala in South India during August and September 2010 among migrant labour population from North and North-east India. Reportedly, the epidemic spread to about 100 individuals in 3 labour Camps within 2 weeks.
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. It is called Disco Rog () meaning weird disease or Jhinjhinani Rog () meaning tingling disease, in that region. 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. It is reported and published in many newspapers like Anandabazar Patrika at that time.
Africa
In the 1970s and early 1980s, newspapers reported incidents of genital shrinking in Western Nigeria. Since late 1996, a small-scale epidemic of genital shrinking was reported in West African nations. 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. Social representations about juju constitute consensual realities that propose both a means and motivation for genital-shrinking experience. 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;
Comparing West African genital-shrinking epidemics with koro in Southeast Asia, the latter has symptoms centered on genital retraction (instead of shrinkage) and fear of death (which is absent in African cases). 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". The name could be derived from a river, its surrounding valley, and a local tribe of the same name which is located at northwestern sector of Sulawesi, Indonesia. The word is also used in Makassarese language, meaning "to shrink"; the full expression is garring koro. or keruk which means "to shrink". The term shuk yang (缩阳), adapted from Chinese, means "the shrinkage of penis".