The Islamic faith is strongly rooted among the Muslim population and may affect the behavior of this group. Most Muslims observe Ramadan, Islam's holy month of fasting. Ramadan begins on the first day of the ninth month of the Islamic lunar calendar. During the month of Ramadan, Muslims abstain from eating, drinking, smoking and engaging in sexual relations from sunrise until sunset to worship Allah and demonstrate their adherence to the doctrine revealed in the Quran of the prophet Muhammad. Some Muslims may choose not to take medication during the hours of fasting. Children, the sick, and women who are pregnant or breastfeeding are exempt from fasting.3,4 It is therefore important for health care workers to know whether patients are observing the month of Ramadan, as this period may lead to metabolic changes (increased levels of uric acid, cholesterol, and thyroid hormones in the blood, and hydrochloric acid in the stomach), nutritional changes (weight loss and dehydration), and mental changes (fatigue and reduced cognitive function); furthermore, diabetic patients may present more frequent episodes of hypoglycemia.5

The Muslim population also presents several unique characteristics in terms of dietary habits. The foods permitted in the Muslim diet are called halal foods. For food to be considered halal, it must conform to the Islamic rules set out in the Quran, the traditions of the Prophet, and the teachings of Islamic lawgivers. According to these rules, the food must be free of any forbidden substance or ingredient or any component from a forbidden animal (pig, wild boar, carrion, animals that have been strangled or beaten to death, animals with claws or fangs, birds of prey or carrion birds, and harmful animals), and must not come into contact with any forbidden product while it is being prepared. Today, Muslim consumers prefer to eat halal products more for sociocultural reasons and reasons of identity than for religious reasons.6 In general, Muslims do not drink alcohol, although this may not always be the case among communities living outside of or marginalized from Muslim populations.4

Muslims tend to see disease as an imbalance between body and soul and believe that it may be the result of failure to comply with the rules governing religious precepts, a belief that makes the individual responsible for the illness.7 It is important to understand the specific characteristics of this population when prescribing treatment: Muslim women do not accept injectable treatments during menstruation; nor should we prescribe syrups, tonics or antiseptics containing alcohol to Muslim patients.4

With regard to physical examinations, it should be noted that Muslim women, like Hindu and Buddhist women, are reticent about undressing and about undergoing vaginal examinations, particularly if they are unaccompanied and the physician is a man.4 Muslims also tend to be reluctant to accept organ donations, transplants, transfusions, or autopsies.4

The Chinese population is the community with the strongest tendency to maintain its own social and family structures and cultural activities and make relatively little contact with local and national social activities in the host country. The family is an essential component in the social life of the Chinese community. For young people, respect for parents, elders, and authority figures such as teachers and masters is very important.8 Chinese women have traditionally been seen as submissive and committed to marriage and family life, but Mao Zedong's cultural revolution and the later westernization of life in China have changed this situation. Equality between men and women has become apparent in practically all aspects of life in modern China.8

The Chinese view health as a question of balance between the forces of yin and yang. Yin represents darkness, the moon, femininity, passiveness, and yielding, whereas yang represents light, the sun, masculinity, activity, and resisting. These principles are not opposing or contrary but complementary and interdependent. Yin and yang are of equal importance, as one cannot exist without the other: light is not the opposite of shadow and that which yields is not the opposite of that which resists. Any deficit or excess in the circulation of this energy produces an imbalance that results in disease.8

In terms of nutrition, there is a belief that some foods are heat-inducing while others are cooling—yin and yang again. For example, pregnancy is considered a hot state and it is therefore considered advisable to reduce the consumption of heat-inducing foods (red meat and fats in general) and increase the intake of cooling foods (fruit and vegetables).8 It is common to see the family members of Chinese patients who have been admitted to hospital bring them the foods that, according to traditional Chinese medicine, are most appropriate for their illness.

Chinese immigrants tend to use medical and social services much less than immigrants from other regions. This may be because Chinese patients are, in general, prepared to suffer more and because they trust in self-administered natural remedies. They also tend to work 12hours a day and thus have little time to visit the doctor, a difficulty that is further compounded by the language barrier.8

Chinese patients consider drips to be a cure-all in the treatment of any illness and prefer drugs that are administered parenterally. In general, they do not accept enemas or suppositories, and are reluctant to have blood taken, as they believe that this weakens their health. They tend to see the loss of teeth as an inevitable consequence of age and rarely visit the dentist.8

Continuous consumption of chapati (a type of wholemeal bread) in Asian communities interferes with the absorption of calcium in the intestines and eventually leads to neonatal hypocalcemia, rickets, and osteoporosis. Chewing betel leaves is also a widespread habit among Asians. Betel is the leaf of a vine grown in South and Southeast Asia. It has somewhat minty flavor, stains the teeth and mucosa a characteristic red color, and can cause kidney stones and mouth ulcers, which occasionally turn malignant.9

Hindus are not allowed to eat beef and those who are vegetarians consume karela or bitter melon, a plant of the cucurbitaceae family that can cause hypoglycemia.4

In Latin-American culture, the concept of disease is closely linked to the body and much importance is placed on physical examinations, additional testing, and the use of technology to diagnose the disease. In contrast to this, Africans sometimes refuse to have blood taken because of the link they have experienced between blood and different practices of witchcraft and black magic.7

It is important to know that, for some immigrant populations, alternative medicines, which are traditional in their country of origin, may continue to play an important role in our country. The use of witch doctors ceases to be important when these populations (particularly Latin Americans) come to Spain, owing to the ease of access to health care. Once in Spain, these populations associate the use of witch doctors with the lack of money and with the culture of their country. Africans are less willing to talk about traditional healing practices and it is possible that they continue to believe in their power and may even continue to use them in Spain.7

The cultural practices of certain immigrant groups can lead to skin abnormalities or the appearance of certain skin diseases. These include coining, cupping, and moxibustion, practices that are usually carried out by Asians.10 Understanding these traditional practices will help us to avoid social and legal conflicts that may arise from mistaken diagnoses of abuse, particularly in children.11

The application of coins (coining) is used to treat febrile diseases in children, headaches, and myalgia. The practice consists of rubbing a coin, usually made of copper or silver, over the skin of the chest or back until the skin becomes reddened or purple.10 The coin is immersed in wine, water, or aromatic oils before being applied.12

The application of suction cups (cupping) is a technique used widely in Asian countries, but also in Eastern Europe. It has been used for different purposes: eliminating toxins from the body, improving illness by transferring the pain to other parts of the body, and in the treatment of pneumonia, asthma, and nephritis.11 Currently the most common use is to treat chronic pain such as lower back pain or headaches.13 The procedure is performed by lighting alcohol-soaked cotton wool and placing it in a cup-shaped receptacle, which is then applied to the skin. As the alcohol burns a vacuum is created, which sucks on the skin. This suction damages the surface blood vessels of the papillary dermis and produces circular areas of erythema, ecchymosis, purpura, or blood-filled blisters. The most common areas of application are the back, chest, abdomen, and buttocks.11

Moxibustion is a common practice among Asians. The aim of the practice is to balance the forces of yin and yang. It consists of burning cones of wood from the Artemisia vulgaris plant close to or on the skin.14 The practice causes circular burns that usually present on the navel, chest, wrists, ankles, and scalp.14

Scarring is another cultural practice used in some African societies. It consists of producing scars on the skin by means of cuts or burns. It is used for both decorative and medicinal purposes.10,14 There is also a custom among the women of some African societies of tattooing their gums for esthetic purposes or as a mark of tribal identity and this should lead us to include racial pigmentation, metal poisoning, tattoos using amalgams, etc. in the differential diagnosis.15

The application of certain products to the hair may lead to the development of certain skin diseases. Mudi-chood is a lichenoid dermatitis that appears on the neck and back of Indian women from the state of Kerala. It is associated with the application of oils to the hair, in combination with the conditions of heat and humidity that obtain in that part of the world.16 There are also differences between the hair of black and white populations. In black people, the curvature of the hair follicles is greater, hairs are flatter and elliptical in shape, making them more fragile, and have fewer elastic fibers; the roots contains more melanosomes and the melanin granules in the shaft are more numerous.10 The biological differences in the hair, together with certain traditional hairstyling practices used among black people (particularly women)—such as hot combs, hair-straightening products, creams, rollers, and extensions—favor the development of alopecia. Two forms of alopecia have been described in this setting: frontal and temporal alopecia10 and central centrifugal cicatricial alopecia on the crown.17–19 The application of hair creams by patients with black skin has also been linked to acne.20

Of note among Latin-American patients are dermatitis due to capsaicin and prayer nodules. Chili peppers are a commonly used condiment in several Latin-American countries. People who manipulate them may present erythema, edema, and pain in the skin of the hands. The capsaicin in the peppers depolarizes the nerve endings, leading to vasodilation, smooth-muscle stimulation and activation of the sensory nerves. It is important to prevent this condition by using gloves. When symptoms appear, the hands should be washed with abundant soap and water and submerged in vegetable oil for an hour; corticosteroids and topical anesthetics may also be used.20

Prayer nodules are calluses caused by pressure on certain points of the body while praying. These nodules have become less frequent since the Catholic Church removed the obligation to kneel during mass, but they are still seen in highly religious individuals—usually elderly Latin-American women—who continue this practice while praying, sometimes for hours.21 These lesions are also characteristic in the Muslim population; Muslims often pray 5 times a day and may present lesions on the forehead, knees, ankles, and dorsa of the feet.22

Another practice found among Muslim women is tattooing with henna or haarqus for social occasions. Allergic contact dermatitis has been described in association with this practice, in most cases due to the presence of paraphenylenediamine in the dye.23,24 Similarly, some Indian women develop allergic contact dermatitis caused by certain components of the bindi, the pigment they apply to their foreheads in certain ceremonies.25

The change in Spain's demographic composition has changed the profile of the patients we see in our clinics. As we have seen, the cultural practices and customs of immigrant populations may favor the appearance of certain skin diseases or modify their form of presentation. Understanding of and respect for the different cultures we live with may be of great help in our routine daily practice.