Hamster hair loss (under chin) Female 19months

[Maggiehammy]

My female Syrian hamster (19 months old approx.)
I have recently noticed a hairless patch under her chin. I have noticed her scratching but i'm not too sure if i'm just hyper-aware of it now I have noticed the balding patch. Although the area I noticed her scratching was more behind the ears. I'm just wanting some advice as to if this might be mites or possibly a reaction to the hay in her cage (she has had the same hay before though). I have attached an image to show her neck before and currently, although the quality isn't great as she very fidgety! Just wanting some opinions before I stress her by taking her to the vets (especially if it is unnecessary), as she is tame but is only used to being handled by me and doesn't particularly enjoy being restrained, rather prefers to walk freely over my hands.

[souffle]

This isn't unusual in hamsters over about 18months. I often see this when I am judging. It's a good idea to check the teeth as overgrown teeth can make them drool and the wet chin can lose fur. Water bottle chewing can also do it. Sometimes it is just getting older though and nothing can really stop it.

[Maggiehammy]

Thank you. Her teeth are not overgrown (she is a huge chewer). I had noticed her neck looking sweaty before the hair loss though. Do you think it could as a result of warmer weather? Although she has access to a large sand bath to cool down in. Hopefully it’s just an age thing as you have suggested.

[Maggiehammy]

Also I have attached a better photo of her neck/chest area (so it's a little easier to see).

[souffle]

It doesn't look red or sore so I'd monitor it for now. They can drool a bit even though the teeth are fine. Hamsters don't sweat like us so it will be from her mouth if she is wet under her chin. Does she chew at the bottle spout at all?

[Maggiehammy]

No she does not chew the water bottle (I have probably seen her try once or twice in her lifetime and quickly stop). I will most certainly monitor it. The only thing that makes me wonder about is the link between it appearing wet/greasy prior to how it looks now. Additionally, she is showing no other signs of older age (no lethargy, appetite loss etc.)
I appreciate all your help, while I have owned hamsters for a long time I haven't had a hamster show baldness during old age (or at any time).
Thank you again for your help (p.s. don't worry, she will go to the vet if she shows any other signs that concern me or becomes worse)

[souffle]

In females it can be hormonal and usually starts about 18 months or so. It can affect the whole belly area with thin belly fur but it never seems to bother them.