Unknown Skin Condition Please help

[y2chloe]

Hello, My rabbit Romi is a healthy two year old holland lop. As I was petting his face I notice he has clumps of matted together hair. Some of the hair has fallen out and some is still connected there is a noticeable white crust on the follicle and surrounding the hair still in the skin. He has a completely bald spot under is chin and some around his mouth he had this when I adopted him. It doesn’t seem like any hair is going to grow back in these spots. Below I’ve added some photos of the affected areas and the hair. Please let me know what you guys think and any tips on what to do. I would take him to the vet but I lost my job because of corona and I can’t afford it. Any tips help

 

[Mariam+Theo]

I think it looks like fur mites or fleas. Check him over for mites and fleas. If it is fur mites, you can treat it with ivermectin. I think you can give him 0.2-0.4 mg/kg, orally every 10-14 days.
http://www.medirabbit.com/EN/Skin_diseases/Parasitic/furmite/fur_mite.htm

 

[Preitler]

I would rather suspect a fungal infection, unusual spots for mites, also because that is a spot that can get damp regularily.

 

[JBun]

I would also say it's a possible fungal infection. Or another possibility is rabbit syphilis. Look at both these links to see how each disease presents and treatment options.
http://www.medirabbit.com/EN/Skin_diseases/Fungal/Fungal_en.htm
http://www.medirabbit.com/EN/Skin_diseases/Bacterial/Syph_gen.html
If he had this when you adopted him, then the shelter/rescue should be responsible for taking care of his treatment since it was a preexisting condition prior to adoption. If it's fungal and that spot is always wet but not just getting wet when he drinks, you could also be looking at a possible dental issue as the root cause resulting in consistent drooling.
http://www.medirabbit.com/EN/Dental_diseases/Differential/D_problems1.htm