Mediterranean tick fever, Mediterranean spotted fever, Marseilles fever, Kenya tick typhus, India tick typhus, Israeli tick typhus; Rickettsia conorii infection;
Fever, eschar at site of tick bite, regional lymphadenopathy, and rash starting on the extremities--affects palms/soles; rash may be petechial; [ID, p. 59, p. 1490]
The eschar begins as a 2-5 mm ulcer and is usually present with the onset of fever. The maculopapular rash follows on days 4-5. The rickettsial infections are characterized by a vasculitis that can lead to organ failure (heart, renal, and respiratory), bleeding, and neurological complications. [CCDM, p. 514-20] The disease is similar to Rocky Mountain spotted fever, but is less severe. [ID, p. 1490] About 10% of patients develop deep venous thromboses late in the course of the illness. In fatal cases, the infection causes vascular injury to many organs including the kidneys, liver, lungs, GI tract, heart, and brain (meningoencephalitis). The percentage of findings in cases series are: tache noire (72%), myalgia (36%), petechial rash (10%), conjunctivitis (9%), stupor (10%), meningismus (11%), splenomegaly (6%), hepatomegaly (13%), jaundice (2%), cough (10%), dyspnea (21%), myocarditis (11%), increased ALT (39%), thrombocytopenia (35%), and azotemia (6%). [PPID, p. 2203; Table 188-1] CNS complications of Rocky Mountain spotted fever and other severe spotted fever infections include meningoencephalitis, seizures, and coma. Signs of pulmonary complications are cough, infiltrates, pleural effusions, and ARDS. [PPID, p. 3271] Direct inoculation of the eye with the blood of an infected tick can cause Parinaud's oculoglandular syndrome. [Guerrant, p. 1005] Lymphadenopathy is present in a minority of cases. Also present are rash (97%) and eschar (50%). [Harrison ID, p. 728] Regional lymphadenopathy is rare. [Cohen, p. 1808] A malignant form of the disease (purpuric rash, shock, and multiple organ dysfunction) may occur in susceptible patients (alcoholic, diabetic, AIDS, debilitated). [Cecil, p. 1958] Nonspecific laboratory findings for rickettsial species infections include elevated transaminases, thrombocytopenia, and leukopenia or leukocytosis. [ABX Guide: Rickettsia species] Fatality rates without treatment: Rocky Mountain (20-25%); Mediterranean spotted fever (1-2.5%); [Cohen, p. 1808]
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