A checklist

Restlessness, irritability and disturbed sleep patterns? Check.
Sore, red gums? Not clear.
Flushed cheeks? Check.
Loss of appetite? If by that you mean lots of little feeds rather than substantial big feeds, then yes.
A slight rise in temperature (but not above 39°C, which indicates a fever)? Check.
Dribbling (which may cause a rash or sore, chapped skin on the chin)? Check.
A sudden desire to chew anything they can lay their hands on? Check.
An urge to bite? Judging by the gum marks on ias's arm this morning, yes.

Either the garklet is turning into a vampire, or he's starting to teethe. He's not shown any sensitivity to either garlic or sunlight, so I assume that the latter is more likely to be the case.