Influenza: Diagnosis, Treatment, Prevention - V.D. Moskaliuk 2010

Influenza
Differential diagnosis

Influenza must be differentiated from acute respiratory infections of other etiologies, which poses considerable challenges. Laboratory Diagnostic Methods play a decisive role in establishing the correct Diagnosis.

Tonsillitis, which shares overlapping symptoms with influenza, is characterized by prominent local changes indicating involvement of the palatine Tonsils: hyperplasia and hyperemia, pus in the lacunae or follicles, as well as submandibular lymphadenitis. However, influenza is frequently complicated by acute tonsillitis or triggers an Exacerbation of chronic tonsillitis. In such associated forms, the general toxicity and other manifestations typical of influenza are preserved.

Ornithosis presents with Upper Respiratory Tract involvement accompanied by fever, though systemic intoxication is moderate. Additional diagnostic indicators include hepatosplenomegaly, a history of contact with birds, a positive intradermal Skin test, and a positive Complement fixation test (CFT) with ornithosis antigen.

Measles, which typically begins with catarrhal symptoms and fever, is indicated by a history of exposure to an infected person and an early pathognomonic sign—Koplik's spots on the buccal mucosa opposite the molars. On days 3–5, a maculopapular rash appears on the HEAD and progressively spreads to the trunk and extremities.

Enteroviral infection often presents with upper respiratory tract involvement. However, epidemic waves typically occur in summer and autumn, and the incidence rises gradually. Alongside clinical presentations resembling influenza, clinicians may observe meningoencephalitis, herpangina, myalgia, pleurodynia, myocarditis, or pericarditis. Poliomyelitis manifests with The Development of paralysis.

Typhoid fever is characterized by an insidious onset, a gradual Temperature rise without chills or profuse sweating, pallor, gastrointestinal symptoms, and Splenomegaly. By the second week, roseolae appear on the abdomen and lateral flanks. The febrile period may persist for several weeks. Salmonella typhi can be isolated from the Blood from the very first days of the illness. It is more challenging to differentiate paratyphoid A and B, which begin acutely with chills, sweating, and upper respiratory catarrh, although they also feature prominent gastrointestinal involvement.

The prodromal period of Viral Hepatitis may present with fever. Nevertheless, headaches are typically mild, upper respiratory catarrh is minimal, and dyspeptic symptoms appear early, accompanied by changes in urine color, subsequent hepatosplenomegaly, and in some patients, jaundice. Serum analysis reveals significantly elevated aminotransferase activity.

The onset of Pneumonia in the first days of illness may go unnoticed because the general manifestations of influenza infection dominate the clinical picture. Therefore, careful attention must be paid to even subtle signs of respiratory failure (such as dyspnea or acrocyanosis), chest tightness, or localized rales. Inflammation of the Paranasal Sinuses is indicated by localized pain over the affected sinuses and purulent nasal discharge. Given the paucity of physical examination findings, modern high-resolution radiographic imaging should be utilized more widely. Valuable diagnostic data (particularly in cases of sinusitis) can be obtained through thermography, which reveals focal hyperthermia in the corresponding anatomical zones with a temperature differential of 1–3 °C.