Types and stages of the disease
Lyme disease goes through a series of stages. But before that, the bacterium needs to multiply in the body during an incubation period. This period is variable, lasting a maximum of 30 days. Throughout this time, patients are usually asymptomatic.
There are three primary stages of the disease, according to its progression. It is possible to treat and cure the disease in all of these stages, and half of the patients without the disease go through all three stages before the immune system takes care of the disease.
The stages of Lyme disease include:
- A stage 1 disease, or early localized disease: This is the first symptomatic stage after the incubation period. It usually starts within 30 days after being bitten and when the condition is only localized in the skin. The most common symptom is an erythema migrans, a type of skin rash we will describe in the section “signs and symptoms.” This stage includes nonspecific symptoms such as headache, fever, chills, fatigue, neck stiffness, and muscle and joint pain.
- A stage 2 disease, or early disseminated disease: Borrelia burgdorferi does not stay in the skin in all patients. It disseminates to the blood and other tissues. This usually happens a few weeks or a few months after the tick bite, depending on each particular case. In this stage, the most common complaint includes musculoskeletal symptoms, cardiac problems, and other skin signs. In this stage, the DNA of B burgdorferi can be found in the skin and bloodstream, sometimes in the cerebrospinal tissue, too, even in patients who do not display neurologic symptoms.
- A stage 3 disease or chronic disseminated disease: This is the final stage of Lyme disease and only happens several months or some years after the tick bite. In some cases, patients go through a latent Lyme disease without any symptoms before starting a stage 3 Lyme disease. In this case, the symptoms are triggered by the immune system reacting against the spirochete in various organs. There is a vast number of possibilities because the bacterium can be found in many organs, as noted above. Thus, the signs and symptoms depend on the type of tissue involved.
We can also say that there are different types of Lyme disease, depending on the Borrelia strain that is infecting the individual. Each one is more commonly associated with specific manifestations. For example, B. burgdorferi sensu stricto is a type of spirochete with a particular tropism to joint tissues. It causes many cases of arthritis in the United States and Europe. On the other hand, B burgdorferi afzelii is another type with intense tropism to the skin tissue and causes a kind of dermatitis known as acrodermatitis chronica atrophicans.