Rocky Mountain Spotted Fever, Lesions on Arm

This is the appearance of the rash of Rocky Mountain Spotted Fever on the hands and forearms. The rash starts on the hands and feet and later spreads to the trunk. It is caused by a bacteria transmitted to humans by a tick bite. (Courtesy of the Centers for Disease Control.)

Deer Ticks

Diseases are often carried by ticks, including Rocky Mountain Spotted Fever, Colorado Tick Fever, Lyme disease, and tularemia. Less common or less frequent diseases include typhus, Q-fever, relapsing fever, viral encephalitis, hemorrhagic fever, and babesiosis.

Ticks

There are many species of ticks. Of these, a large proportion are capable of carrying disease. Diseases carried by ticks include Lyme disease, Erlichiosis, Rocky Mountain Spotted Fever, Colorado Tick Fever, tularemia, typhus, Q fever, hemorrhagic fever, and viral encephalitis. (Courtesy of the Centers for Disease Control.)

Rocky Mountain Spotted Fever on the Arm

Rocky Mountain Spotted Fever is a disease transmitted to humans by a tick bite. The spots begin as flat (macular) red (erythematous) patches that may bleed into the skin, causing purplish spots (purpura). The disease is named after its characteristic spots. (Courtesy of the Centers for Disease Control.)

Tick Imbedded in the Skin

This is a close-up photograph of a tick embedded in the skin. Ticks are important because they can carry diseases such as Rocky Mountain spotted fever, tularemia, Colorado tick fever, Lyme disease, and others.

Rocky Mountain Spotted Fever on the Foot

Rocky Mountain spotted fever is caused by the organism Rickettsia rickettsii and is transmitted by a tick bite. It is a serious infection that produces a classical rash in about 90% of infected individuals. This is the typical appearance of the rash. There are many symptoms that affect the entire body (systemic).

Rocky Mountain Spotted Fever, Petechial Rash

Rocky Mountain Spotted Fever is a potentially fatal infection transmitted to humans by ticks. This photograph shows the classical appearing rash which often begins on the wrists and ankles, and spreads rapidly towards the center of the body. The rash may also be present on the palms and soles.

Antibodies

Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.