Antiemetics are typically used to treat motion sickness and the side effects of medications such as opioids and chemotherapy.Antiemetics act by inhibiting the receptor sites associated with emesis. Hence, anticholinergics, antihistamines, dopamine antagonists, serotonin antagonists, and cannabinoids are used as antiemetics.Evidence to support the use of antiemetics for nausea and vomiting among adults in the emergency department is poor. It is unclear if any medication is better than another or better than no active treatment. Epidemiology
Nausea and/or vomiting are the main complaints in 1.6% of visits to family physicians in Australia. Society and culture
Herodotus, writing on the culture of the ancient Persians and highlighting the differences with those of the Greeks, notes that to vomit in the presence of others is prohibited among Persians. Social cues
It is quite common that, when one person vomits, others nearby become nauseated, particularly when smelling the vomit of others, and often to the point of vomiting themselves. It is believed that this is an evolved trait among primates. Many primates in the wild tend to browse for food in small groups. Should one member of the party react adversely to some ingested food, it may be advantageous (in a survival sense) for other members of the party to also vomit. This tendency in human populations has been observed at drinking parties, where excessive consumption of alcoholic beverages may cause a number of party members to vomit nearly simultaneously, this being triggered by the initial vomiting of a single member of the party.
Aplasia cutis congenita  is a rare disorder characterized by congenital absence of skin. Frieden classified ACC in 1986 into 9 groups on the basis of location of the lesions and associated congenital anomalies. The scalp is the most commonly involved area with lesser involvement of trunk and extremities. Frieden classified ACC with fetus papyraceus as type 5. This type presents as truncal ACC with symmetrical absence of skin in stellate or butterfly pattern with or without involvement of proximal limbs. It is the most common congenital cicatricial alopecia, and is a congenital focal absence of epidermis with or without evidence of other layers of the skin.The exact etiology of ACC is still unclear but intrauterine infection by varicella or herpes virus, drugs such as methimazole, misoprostol, valproate, cocaine, marijuana etc., fetus papyraceus, feto-fetal transfusion, vascular coagulation defects, amniotic membrane adherence, abnormal elastic fiber biomechanical forces and trauma are implicated. It can be associated with Johanson–Blizzard syndrome, Adams–Oliver syndrome, trisomy 13, and Wolf–Hirschhorn syndrome. It can also seen with exposure to methimazole and carbimazole in utero. This dermatological manifestation has been linked to Peptidase D haploinsufficiency and a deletion in Chromosome 19. Signs and symptoms
Genetics
This condition has been linked to mutations in the ribosomal GTPase BMS1 gene. Diagnosis
Treatment
Skin grafting is a solution to fix aplasia cutis congenita. See also
List of cutaneous conditions

References
External links
Aplasia cutis congenita (ACC) on emedicine