Sorry I took so long
Almost certainly this is pododermatitis...classic signs
Feline Plasma cell pododermatitis (Pillow Foot) is a foot pad disease of cats that is poorly understood but well recognised. The condition involves the infiltration of one or more foot pads by plasma cells, a type of lymphocyte (white blood cell). The problem is considered to be an immunological problem. Occasionally affected cats are infected with the Feline Immunodeficiency Virus (FIV) but not always so it is important to blood test for this although a definite link has not been established.
Affected pads become puffy and swollen and may develop a purplish tint. Usually the pads of more than one foot are affected. Generally there is no pain associated with the problem but occasionally ulceration will occur and that can cause lameness and a potential for secondary bacterial infection. There is no particular gender, breed or age predisposition.
Diagnosis is often simply made on the appearance of the lesions and the distribution (multiple pads) but biopsy can confirm it.
Traditionally corticosteroids (eg prednisolone, prednisone) have been used for this condition with varying results but often the response is only temporary. For several years I have now been using the more recently recommended medication doxycycline. This is an antibiotic that has an unusual anti-inflammatory side effect. It is well tolerated by cats, rarely causing any side effects. To be effective it must be used continually for a month or two at a dose of around 5mg/kg (2 mg/lb) twice daily. Use it for at least 2 weeks after the pads have returned to normal. The first signs of a response usually occur within 7-10 days.
Some owners elect to not treat. In milder cases this may be reasonable but there are no topical medications that will control the problem. I would definitely treat if it was my cat.....drag him out from under the bed!
I find almost 100% success with this treatment. Of course you will need to see your vet about it. Be warned that I have found that some vets have not heard of this so take the name with you “Feline Plasma Cell Pododermatitis”.
I hope this has been of help. Please contact me back if I can assist further.
Kindest regards, Peter