'Thumbprint' sign seen in –
Thumbprint sign is a finding on lateral cervical spine radiograph that suggest diagnosis of epiglottitis. This appearance is due to thickening of aryepiglottic folds, which causes it to appear more radiopaque, resembling the distal thumb.

Also know

Thumbprint sign is also seen in the colon in following diseases :- (1) Ulcerative colitis; (2) Ischemic colitis; (3) Crohn's colitis; (4) Pseudomembranous colitis; (5) Amebic colitis; (6) Schistosomiasis; (7) Lymphoma; (8) Metastasis; Pneumatosis coli.
Candida
Asp ergillus
Thrrmomyces
Epiglotitis