Staph infection

"Staph infection" nearly always means Staphylococcus aureus. Laboratories then split it into two groups by antibiotic susceptibility: MSSA, which responds to the ordinary penicillin-family drugs, and MRSA, which does not. The bacterium is the same shape, spreads the same way and causes the same infections; only the treatment changes. See MSSA vs MRSA for the full comparison.

On the skin, staph produces a small set of recognisable patterns. Almost everyone searching for pictures is looking at one of these:

• Boil or abscess — a deep, painful, pus-filled lump. Full detail
• Folliculitis — small pus-topped bumps around hair follicles. Full detail
• Cellulitis — a flat, spreading, hot red area rather than a lump. Full detail
• Infected wound — a cut or surgical site that turns red, weeps and stops healing.
• Something taken for a spider bite — the most common first impression. Staph vs pimple

For a stage-by-stage walkthrough of every appearance, see what does a staph infection look like — or the resistant-strain version, what MRSA lesions look like.

Yes, by contact rather than through the air. It travels on hands, on skin-to-skin contact and on shared objects — towels, razors, bedding, gym equipment, dressings. Intact skin is a good barrier, so the risk is concentrated where skin is broken. A draining lesion is treated as contagious until it is covered, dry and healing.

The full answer — how long someone stays infectious, household rules, and when school, work and sport are safe again — is on is a staph infection contagious? The setting-by-setting version for resistant strains is on is MRSA contagious?

The single most important step for an abscess is drainage; antibiotics alone often will not clear a walled-off collection of pus. Which antibiotic follows depends on the culture result:

Which antibiotics cover staph, which never will, and how long courses run is set out on antibiotics for a staph skin infection. The full drug-by-drug picture is on every MRSA antibiotic, and the practical treatment path is on treating skin and soft-tissue infection.

• Fever or chills alongside a skin lesion
• Redness spreading quickly, or red streaks running from the wound
• Severe pain, or a lesion growing by the hour
• Any significant lesion in a baby, or in someone with diabetes, cancer treatment or a weakened immune system
• Confusion, breathlessness or feeling profoundly unwell — see when staph and MRSA become dangerous

Wash hands, keep wounds covered until healed, do not share towels or razors, wash bedding and towels hot, and clean shared gym equipment before use. If infections keep returning in the same person or household, ask a clinician about decolonisation and read why MRSA keeps coming back.