<s>[INST]sudden sharp pain like wasp sting or spider bite. shoes on at time,  dark blue discoloration of toe at joint beneath toe gradually spreading to neighboring toes as if briuised  - pain was transitory not due to impact or stress, not tender to touch, no visible punctures, not distended or firm,[/INST]Pain and dark blue discoloration of toe suggests decreased blood flow to that part and as a result poor oxygen supply to the nerves and tissues there. It may be triggered either by exposure to cold (Reynolds phenomenon) or a peripheral arterial disease phi you have risk factors like diabetes, hypertension/chronic smoker. Both of these needs complete clinical evaluation, and you need to meet a doctor and might have to do some tests</s>