An adherent, dense, grey pseudomembrane covering the tonsils is classically seen in<unk> . A<unk>  skin lesion on the leg The symptoms of<unk>  usually begin two to seven days after infection. They include fever of 38 °C (100.4 °F) or above; chills; fatigue; bluish skin coloration (cyanosis); sore throat; hoarseness; cough; headache; difficulty swallowing; painful swallowing; difficulty breathing; rapid breathing; foul-smelling and bloodstained nasal discharge; and lymphadenopathy. Within two to three days,<unk>  may destroy healthy tissues in the respiratory system. The dead tissue forms a thick, gray coating that can build up in the throat or nose. This thick gray coating is called a "pseudomembrane". It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow. Symptoms can also include cardiac arrhythmias, myocarditis, and cranial and peripheral nerve palsies.<unk> ic croup Laryngeal<unk>  can lead to a characteristic swollen neck and throat, or "bull neck". The swollen throat is often accompanied by a serious respiratory condition, characterized by a brassy or "barking" cough, stridor, hoarseness, and difficulty breathing; and historically referred to variously as "diphtheritic croup", "true croup", or sometimes simply as "croup".<unk> ic croup is extremely rare in countries where<unk>  vaccination is customary. As a result, the term "croup" nowadays most often refers to an unrelated viral illness that produces similar but milder respiratory symptoms.
Diphtheria
Spanish flu
Swine influenza
Plague 
Anthrax
Periodic fever syndrome
Murine typhus
Influenza