If the same diagnostic methods are used, the rates are similar between countries. ADHD is diagnosed approximately three times more often in boys than in girls. This may reflect either a true difference in underlying rate, or that women and girls with ADHD are less likely to be diagnosed.Rates of diagnosis and treatment have increased in both the United Kingdom and the United States since the 1970s. Prior to 1970, it was rare for children to be diagnosed with ADHD, while in the 1970s rates were about 1%. This is believed to be primarily due to changes in how the condition is diagnosed and how readily people are willing to treat it with medications rather than a true change in how common the condition is. It was believed changes to the diagnostic criteria in 2013 with the release of the DSM-5 would increase the percentage of people diagnosed with ADHD, especially among adults.Due to disparities in the treatment and understanding of ADHD between caucasian and non-caucasian populations, many non-caucasian children go undiagnosed and unmedicated. It was found that within the US that there was often a disparity between caucasian and non-caucasian understandings of ADHD. This led to a difference in the classification of the symptoms of ADHD, and therefore, its misdiagnosis. It was also found that it was common in non-caucasian families and teachers to understand the symptoms of ADHD as behavioral issues, rather than mental illness.Crosscultural differences in diagnosis of ADHD can also be attributed to the long-lasting effects of harmful, racially targeted medical practices.
Tick-borne diseases like Rocky Mountain spotted fever produce a rash that may become extensive enough so as to be classified as exanthemous in as many as 90% of children with the disease. See also
List of cutaneous conditions

References
External links

Overview at About.com
Definition at MedTerms
Differential diagnosis
Dermatology Quiz Includes photo, diagnosis, and treatment of unilateral laterothoracic exanthem (ULE).