I have been on antibiotics for a leg inf

Yes — treat this as same-day, not a watch-it-tonight thing. A pocket of pus that went from a few millimetres to about an inch (2.5 cm) in a couple of hours, while you are already on antibiotics, needs a clinician to look at it today. If none of the red flags below are present, the urgent care that opens at 8am is a reasonable door. If any of them are present, go tonight.

I am not a doctor and this is not a diagnosis. What this is, and whether the antibiotic needs to change, is a clinician's call today, not tonight's — I can't decide either, and I won't guess. What I can do is get you through the next few hours safely and get you to the right door with the right words.

Not covered here, on purpose: naming the condition, changing or adding any medicine, working out doses, and any test result. Those all belong to the clinician who sees it.

One thing first: the photo you took of your leg did not come through to me — I cannot see it. If you send it again, with the pen mark and the whole area in frame in good light, it goes into the record you take with you. The care below does not depend on it.

1. What you have tried, and the better alternative

Squeezing it: stop. Pressing a pocket like this can push infection into the surrounding tissue, and the "whoosh" relief is not the infection leaving. From now on: hands washed, nothing squeezed, nothing pierced, nothing drained, no plasters over the head of it. Do not clean inside it or dab with anything.

Pen mark around the edge: good — that is one of the most useful things you did. Write the time next to the line. Then do this three times before morning: put a ruler or a coin next to it, take one photo straight-on with the time in the frame, and glance at it. That is 2 minutes each time, about 6 minutes total, and it is the one thing that tells the clinician whether it moved.

Better alternative tonight, in order: cover it with a clean dry dressing (gauze and tape, or a clean cloth held on loosely) so nothing rubs on clothes or bedding; change it if it soaks through; prop the leg up on a pillow when resting, above hip level; keep the water bottle and regular meals going so nobody in the house skips food because of the school run; keep the medicine exactly as it was prescribed to you — same times, no doubling after a missed one, no stopping early, no leftover antibiotics from anyone else's drawer.

A cool clean cloth on the area for 10 minutes at a time is fine if it soothes. Nothing frozen, nothing glued, no pastes, powders, or "drawing" salves from the cupboard or the internet — and no buying prescription antibiotics or powders online.

2. The avoid list

• Do not squeeze, poke, needle, or burst it, and do not let anyone else do it.
• Do not change, stop, restart, or add any antibiotic, painkiller, or cream. That is the prescriber's call today, not tonight's.
• Do not use leftover medicine from another person or another illness, and nothing bought online without a prescription.
• Do not apply ice, a heating pad, pastes, powders, or herbal salves. No home "drawing" remedies.
• Do not share towels, and do not wash the area with scrubby soap. Clean water, pat dry, no scrubbing.
• Do not wait for the redness to "settle down" over the next two days. That waiting rule is for people who are already under a clinician and improving — yours is moving the wrong way.
• Do not let the school run, the evening, or "it's quieter in the morning" decide this. The pocket has a schedule of its own.

3. Decision tree — read top to bottom

Stop and go to an emergency department tonight, or call your local emergency number now, if any one of these is true:

• Redness or swelling has moved past the pen line, or red streaks are running up the leg.
• The pain is worse than the area looks — out of proportion, deepening, or hard to sit through.
• Fever with shaking chills, or confusion, drowsiness, or feeling "not right" — that last one in an adult with an infection is not something to sit on.
• The skin is going dusky, dark, purple, blistering, or crackling under the touch; or the leg is swelling from the knee to the ankle and pitting when you press it.
• Fast breathing, a racing heart, the room spinning on standing, or not keeping fluids down.
• The foot is cold, pale, numb, or weak.

If none of those, and they are eating, drinking, alert, and the pain is bearable: get to urgent care when it opens at 8am, first appointment of the day if you can. That is the door for today.

What usually happens at that appointment (so nothing is a shock): a clinician looks at it, often measures and marks it the same way you did, and usually the treatment for a pocket like this is a small procedure to let it drain, plus a decision about the antibiotic — sometimes the same one continues, sometimes it changes, sometimes a swab is sent. Some of that happens in urgent care, some sends you to a hospital clinic. Bring the medicine box or a photo of the packet.

What success looks like in 24 hours — and I will not promise you a cure: you are seen, and by the time you go in you can say, in order: this is when it started, this is the time on the pen mark, this is what it looked like at that time in the photo, this is what I have been taking and since when, and this is what should make me come straight back. That is the win tonight. If after being seen it grows again, or a red streak appears, that is a return — not a "wait and see".

The script to say or send (screenshot this):

"Leg infection, I have been on antibiotics since [date] as prescribed. A pocket of pus has grown from a few millimetres to about an inch in a couple of hours. I marked the edge with a pen at [time] and photographed it. I have not squeezed it. I have [no fever / fever since ___]. My questions: does this need draining today, do I keep taking the antibiotic exactly as prescribed, what should bring us straight back, and what must I not do at home?"

To whoever covers the house tonight, in one line: "Leg pocket, growing fast, no squeezing, dressed, if it goes past the pen line or they get feverish or spaced-out, we go to emergency tonight — I don't need a debate about it."

If you send the photo again, send one with the pen mark in frame and one close-up, in daylight if you can. And if any line in section 3 is true tonight, do not wait for morning and do not wait for my reply.