What inflammation looks like up close and personal, part IV

Here’s another snippet from the first chapter of my new book, How Your Child Heals. It’s from the chapter about inflammation, and follows from here. You’re at the battlefield of inflammation, a sore finger, and are positioned to observe the conclusion of the struggle.

How did those germs get through the barrier of your son’s skin to cause infection? As you approach the epicenter of the action, you discover the answer. Sometimes germs can simply crawl through the skin via a small break, but other times they have an accessory to aid their attack. Up ahead you now can see that the bacteria gained entry to his finger through a break in his skin caused by a small wood splinter. The tip of the splinter stands in the center of the cellular fray, marking the spot where it began.

Like most battles, the outcome of this one can go either way. If the body’s defenses win, the immediate result is what we call an abscess, a walled-off pocket containing dead phagocytes and dead bacteria. This is the whitish pus we have all seen beneath the skin of an infected area, such as a skin boil. Usually, there are also some living bacteria remaining in the pus, the relative amount of which depends upon how many were there at the beginning—generally, the phagocytes cannot kill them all. But any remaining living bacteria are now at least cordoned off, contained within the protective barrier walls of the abscess.

If the germ attackers win the initial battle, no abscess forms. Rather, the bacteria breach the body’s initial defenses and spread through the body, sometimes by using the bloodstream, but other times just by marching through the tissues. When that happens, the child is generally quite obviously ill with fever and other symptoms, such as chills, muscle aches, and a general malaise. These symptoms come from all of those substances that got the inflammatory response going at the site of invasion—the signals calling the phagocytes and the auxiliary cells. Only now these substances are not just in one spot and exerting their effects there; they are circulating throughout the child’s entire system. When that happens, it is usually a sign the child’s body will need help dealing with the infection, such as antibiotic treatment.

The formation of an abscess is an immediate victory for the body, but it still represents a kind of standoff between the attacking bacteria and the body’s defensive systems. The residual bacteria can still cause problems. For one thing, the toxins they release leak out into the regions surrounding the abscess and inflame those areas, too. Plus, the dead and dying phagocytes also give off substances that keep the fire of inflammation burning. For these reasons the area surrounding the abscess usually continues to be at least a little inflamed—red, swollen, and painful.

The bacteria remaining in an abscess can cause further problems, even though they failed in their first attempt to invade further. If they are still very numerous, they continue to reproduce, and they can do so very quickly—doubling their numbers every hour or less. Reinforced by all these new recruits, they can overwhelm the local defenses, break through the abscess walls, and spread throughout the body. One important thing that can aid bacterial growth is the presence of a bit of material foreign to the body, such as the splinter that is still in your son’s finger. Phagocytes have a much more difficult time searching down and eradicating bacteria if there is something like that in the wound that gives the bacteria a place to hide.

You have now witnessed close up the complicated drama of what happens during what you may previously have thought was a simple matter—your child getting a small infection at the end of his finger. What you have seen are the early and middle stages of inflammation, the principal way our bodies fight off infections like the one on your son’s finger. The same sequence of events happens on a larger scale when the initial injury and bacterial invasion is much larger. The larger the battlefield, the higher the stakes. For even the smallest abscess, a child’s body usually benefits from a little help to handle the problem or at least to make it heal more quickly. Larger, more serious infections nearly always require help. So, having seen enough, you finally turn your craft around and leave the area. After all, you have to call the doctor’s office to find out what to do about all of this.

You can read about how the battlefield of inflammation heals in a later post.