HME, caused by the bite of the tick Amblyomma americanum infected with E. chaffeensis, causes an illness not unlike RMSF, except a rash usually does not occur. Diagnosis is usually made serologically, and treatment of choice is tetracycline. Symptoms include high fever, severe headache, and myalgias. EM is the characteristic skin lesion seen in Lyme disease. HME is transmitted by a tick vector, as mentioned previously, and not by a dog bite. Vomiting and paralysis are not usual symptoms seen in HME cases. Cultures can be isolated using tissue culture cell lines, but not artificial media (agar, broth, etc.).