Viral Exanthem (e.g., Viral Rash): This is the most likely diagnosis given the combination of fever, pruritic maculopapular rash, and respiratory symptoms like colds and dry cough. Many viral infections can cause such a presentation, and the symptoms are consistent with a self-limiting viral illness.

Infectious Mononucleosis (Mono): Caused by Epstein-Barr virus (EBV), it can present with fever, rash, and respiratory symptoms. The rash in mono can be maculopapular and may appear after the onset of fever.
Secondary Syphilis: This condition can cause a maculopapular rash on the trunk and arms, along with fever and other systemic symptoms. The rash of secondary syphilis is often accompanied by lymphadenopathy.
Kawasaki Disease: Although more common in children, Kawasaki disease can occur in adults and presents with fever, rash, and other systemic symptoms. However, it typically includes more specific criteria like conjunctival injection and changes to the lips and oral cavity.

Meningococcemia: This is a life-threatening condition caused by Neisseria meningitidis. It can present with fever, rash (which can be petechial or purpuric), and respiratory symptoms. Early recognition and treatment are crucial.
Rocky Mountain Spotted Fever (RMSF): Caused by Rickettsia rickettsii, RMSF can present with fever, rash (which often starts as maculopapular and can become petechial), and other systemic symptoms. It is critical to consider this diagnosis in individuals who have been exposed to ticks.
Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN): These are severe skin conditions usually triggered by medications or infections. They can present with fever, rash, and mucosal involvement. Early recognition is vital due to the high morbidity and mortality associated with these conditions.

Erythema Multiforme: A skin condition characterized by target lesions, often triggered by infections or medications. It can present with fever and rash but is less likely given the description of a pruritic maculopapular rash.
Pityriasis Rosea: A condition that causes a rash, often preceded by a herald patch, and can be accompanied by fever and pruritus. However, the rash typically has a distinctive distribution and appearance that might not fully match the description provided.