Ticks are small arachnids that feed on the blood of mammals, birds, and sometimes reptiles and amphibians. While the idea of ticks may seem harmless, they can carry a number of diseases and allergens that can be harmful to humans and animals.
Tick-borne diseases prevalent in the United States encompass Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, tularemia, babesiosis, Colorado tick fever, and relapsing fever. Family physicians must consider these ailments when patients exhibit influenza-like symptoms.
Notably, a rash initially appearing on the palms and soles is indicative of Rocky Mountain spotted fever. In contrast, erythema migrans—an annular macule with central clearing—is characteristic of Lyme disease. Various other rashes or skin lesions accompanied by fever and flu-like symptoms may also indicate a tick-borne disease.
Early and precise diagnosis is critical for effective treatment and can significantly reduce morbidity and potential mortality. Since infection typically requires 24 to 48 hours of tick attachment to the host, prompt removal of ticks can aid in preventing disease transmission. Treatment with doxycycline or tetracycline is recommended for conditions such as Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, and relapsing fever.
In cases where clinical signs are suggestive of a tick-borne illness, initiating treatment should not be postponed pending laboratory confirmation. Conversely, treatment is not warranted if no symptoms manifest following exposure to tick bites—a single tick bite has the potential to transmit multiple infectious pathogens concurrently.
Advising patients on measures to prevent tick bites—particularly during the summer months—can effectively mitigate exposure risk to these hazardous vector-borne diseases.
In addition to these diseases, ticks can also carry allergens that can cause allergic reactions in some individuals. The saliva of ticks contains proteins that can trigger an allergic response in some people, leading to symptoms such as itching, redness, and swelling at the site of the tick bite.
To protect yourself from tick-borne diseases and allergens, it is important to take precautions when spending time outdoors in areas where ticks are common. This includes wearing long sleeves and pants, using insect repellent, and checking yourself and your pets for ticks after spending time in wooded or grassy areas.
Recognizing specific symptoms and red herring conditions is sometimes even more critical. For example, diagnosing Lyme disease is fraught with challenges. A significant number of patients do not exhibit the hallmark symptom, erythema migrans (EM), whether or not it is accompanied by its characteristic bull’s-eye rash. Additionally, other associated symptoms such as fever, chills, fatigue, and headache lack specificity. Often individuals infected with this tick-borne illness may not recall being bitten by a tick. The diagnosis complexity is further heightened by the fact that testing for Lyme disease lacks precision.
Consequently, there are instances where individuals suffering from Lyme disease receive incorrect diagnoses for other conditions including fibromyalgia, rheumatoid arthritis, and multiple sclerosis (MS). These chronic diseases are among several illnesses that could be confused with Lyme disease – including the summer flu, an off season infection of the common upper respiratory virus, influenza.
This makes the treatment of many diseases difficult, particularly given the time sensitivity of treatment. For certain conditions, the immediate initiation of appropriate antibiotic therapy is crucial, such as when Rocky Mountain spotted fever, ehrlichiosis, or relapsing fever is suspected. This is in contrast to waiting for laboratory confirmation.
Treatment with doxycycline (Vibramycin) or tetracycline is advised for conditions such as Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, and relapsing fever. Preventative measures against tick-borne diseases include avoiding tick-infested areas; wearing long pants and tucking pant legs into socks; applying insect repellents containing N,N-diethyl-m-toluamide (DEET); using bed nets while camping; and regularly inspecting oneself in at-risk areas. For suspected cases of tularemia, empirical treatment with streptomycin or gentamicin should be administered prior to obtaining laboratory confirmation.
But these instances of immediate antibiotic use are the exception rather than the norm. Antibiotic prophylaxis following a tick bite to prevent Lyme disease is generally not recommended unless there is a high risk of infection. The wide ranging clinical recommendations and acuity of treatment window makes treating tick borne diseases difficult.
The best treatment is preventive. But in cases where symptoms are suspicious, immediate clinical evaluation from a professional is warranted.
