Hello dear Greetings Regarding your husband symptoms of red coloration at the feet ankle and the lower leg I am suggesting the following differential diagnosis Cellulitis Diabetes Peripheral vascular disease Myositis Tendonitis Trauma Idiopathic thrombocytopenia In view of this please let him do the following test Blood culture Fasting blood sugar Doppler scan ESR Complete blood count Meanwhile please see your physician with the result and for further expect clinical assessment and adequate drug prescription I hope this helps