Questionnaire/history:

Rapid onset of pain, swelling, redness and usually visible pus under the skin? 

Examination:

Swelling, redness and usually visible pus under the skin, limited to beyond the distal interphalangeal joint and on the dorsal aspect of the finger?

Vesicles?

Management:

Flucloxacillin: spreading infections with redness tracking up the finger proximal

Drainage: small abscesses

Clean the distal finger using an alcohol wipe 

Provide short-acting analgesia in the form of ethyl chloride freeze spray, ice water soak or very cold running water immersion 

Slide the blunt side of a small scalpel or a green needle or similar over the nail to under the cuticle to liberate the pus from the paronychial space 

Gently express any pus that is present 

Dressing with a simple plaster

Patient can then soak the finger in warm water intermittently for a day or two which will keep the communication open and allow any other infection to leave the finger

Herpes simplex infection ("herpetic whitlow"): topical or oral antivirals 

Chronic paronychia:

(Note: considered likely an inflammatory condition rather than a chronic infection)

Topical steroids and avoidance of triggers, which are often occupational

Some chronic paronychias are treated surgically involving more than a simple release and requiring several follow-up visits

Reference(s):

Dermnet 

EMJ 2005