Chemical Burn or Irritation: This is likely due to exposure to fireworks chemicals, which can cause skin hyperemia and irritation, including the bulbar urethra if exposed.

Thermal Burn: Direct exposure to fireworks can cause thermal burns, leading to hyperemic skin and potential damage to the bulbar urethra.
Allergic Reaction: Some individuals may have an allergic reaction to components of fireworks, such as certain metals or chemicals, leading to skin hyperemia and other symptoms.
Urinary Tract Infection (UTI): Though less directly related to fireworks, a UTI could cause discomfort in the urethral area and might be considered if other symptoms like dysuria or frequency are present.

Testicular or Scrotal Trauma: In cases of severe exposure or accidents involving fireworks, trauma to the genital area must be considered to prevent missing serious injuries.
Urethral Stricture or Injury: Direct trauma from an explosion or severe burn could potentially injure the urethra, leading to strictures or other complications that need immediate attention.

Systemic Toxicity from Firework Chemicals: Certain chemicals in fireworks, like heavy metals, could potentially cause systemic toxicity if ingested or absorbed through burns, though this would be rare and depend on the composition of the fireworks.
Infectious Diseases from Contaminated Fireworks: Though highly unlikely, if fireworks are contaminated with infectious agents (a very rare scenario), exposure could potentially lead to infection, especially in the case of open wounds or compromised skin integrity.