Chart 1.

Skin manifestations caused by tick bites in humans

Cause		Skin manifestations
Primary lesions
Immediate reactions	Toxins and irritants in saliva	Firm papules, intense pruritus. The tick can be attached.
Late reactions	Fragments of the mouthpart	Chronic edematous nodule, similar to a foreign body granuloma.
Secondary lesions
Lyme Borreliosis	Borrelia spp. complex (spirochetes)	Erythema migrans (centrifugally progressing plaque, "bull's eye"), lymphocytoma cutis, sclerodermiform states.
Rocky Mountain Spotted Fever	Rickettsia rickettsii	Hemorrhagic rash with petechiae and hemorrhagic suffusion that can become necrotic.
Tick paralysis	Neurotoxins in saliva	Ascending progressive paralysis that can lead to death. Ticks attached to the skin.
Ehrlichiosis	Ehrlichia canis (bacterium)	Erythematous or erythematous-purple non-specific rash.
Recurrent fever	Borrelia recurrentis (spirochete)	Non-specific erythematous rash.
Tularemia	Francisella tularensis(Gram negative coccobacillus)	Deep ulcer on the site of the bite and swollen regional lymph nodes.
Babesiosis	Babesia canis (protozoan)	No cutaneous manifestations.