A 7-year-old boy with a history of asthma was brought to the emergency department by his parents because of a “strange” rash on the chin. The parents noticed the rash when he awoke in the morning. It was not painful or pruritic. The child could not recall any trauma to his chin but had been coughing and complaining of a sore throat. He had no fever or vomiting.
On examination, vital signs were normal. The child was smiling and in no distress. His throat was mildly erythematous. He was breathing comfortably but had bilateral wheezes on auscultation. An area of nontender petechiae and purpura was noted on the chin. The remaining examination findings were normal.
Results of a rapid streptococcus test were positive. The patient was treated with nebulized albuterol, after which the wheezing resolved.
The list of diagnoses associated with petechiae or purpura is long. It includes rare and dangerous diseases, such as meningococcemia, Rocky Mountain spotted fever, and coagulopathies, as well as more common causes, such as trauma and viral illness. In general, coughing or vomiting can produce a petechial, sometimes purpuric rash that is limited to the area above the nipple line. In such instances, the rash is usually poorly localized and concentrated around the cheeks and eyes. Group A streptococcus pharyngitis can also be associ-ated with a diffuse petechial rash.1 Although the patient and parents denied any trauma, nonaccidental injury should always be a consideration.
In this case, after a thorough review of the patient’s medical and family history, the cause of the chin purpura remained unclear. Through an Internet search for “chin and purpura,” we quickly found 2 reports on factitious purpura that described children who had sucked on the edge of a cup after placing it over the chin.2,3 On further questioning, the parents recalled the child sucking on a cup in this way the previous evening.
Factitious purpura is a mechanical rash intentionally or inadvertently inflicted by the patient. There have been only a handful of reports of this type of purpura in children, all of whom were aged between 9 and 16 years.4 Factitious purpura is most often caused by suction, as in this case.5
The diagnosis of factitious purpura, through the Internet search and further questioning of the parents, prevented a potentially costly and uncomfortable evaluation. The family was reassured that the child’s rash was benign and would resolve spontaneously over the next week.