Carphologia
Carphologia (or carphology) is a lint-picking behavior that is often a symptom of a delirious state.
Often seen in delirious or semiconscious patients, carphologia describes the actions of picking or grasping at imaginary objects, as well as the patient’s own clothes or bed linens. This can be a grave symptom in cases of extreme exhaustion or approaching death.
Wikipedia
Carphologia (noun)
picking at bedding and clothing, or at the lips, or of perceived invisible objects
Wiktionary