Within 2 to 6 weeks of acute HIV-1 infection, some infected patients may develop systemic symptoms resulting from HIV viremia and acute damage to the immune system, involving the skin, nervous system, and gastrointestinal tract. Fever, rash, myalgia and headache are most common. 10% to 15% of patients have mononucleosis-like manifestations. The clinical symptoms that occur during the acute infection period are mostly self-limiting, and most patients have mild symptoms that can resolve on their own after 1 to 3 weeks.