Wound swells up shortly after vaccination. Exposure demonstrated?

Factual Questions
1

Somebody got scratched by a rabid cat, and a week later starts the series of shots for preventing rabies. The small wound, which had healed quickly and easily, pretty suddenly swelled up and got inflamed and bumpy and hot shortly after the first shots. Does this demonstrate that the wound was in fact a rabies virus exposure, and the immune system has kicked into high gear locally?

2

I hope this isn’t a “Need Answer Fast” question.

IANAD but I wouldn’t assume that it meant that rabies was present. It’s more likely to be some sort of allergic reaction to the treatment, and I personally would recommend going back to the doctor to get it checked out, especially if it doesn’t go away quickly. It could just mean that there was a bacterial infection at that site and the vaccine was reacting to whatever was going on with the bacteria and your immune system there. Or something else; I repeat -> not a doctor.

This siteseems to suggest that allergic reactions of various kinds to the rabies vaccine are not unusual:

3

IAAD, but this isn’t my area of practice so unfortunately I have only theoretical knowledge and no practical experience to offer. In theory, the rabies immunoglobulin (pooled preformed antibodies directed against the virus) seem to be eliciting a response to something. To my mind it’s logical to assume it is to some substance associated with the virus. But it would not have to be whole live virus - maybe just fragments of it or something else that commonly travels with it.

I echo the recommendation to report it ASAP.

4

I am also not a doctor. I think it is very unlikely to get rabies from a scratch. Rabies is transmitted through saliva. Some other kind of infection from the scratch seems more likely to me.

I was once attacked by a cat and a pitbull simultaneously(long story). The cat scratches ended up being much worse than the dog bites. They got hot, inflammed, swelled up, and pretty painful.

5

That’s a good point - the two things (scratch inflammation and rabies shots) may be unrelated. For example, cat scratch fever is more than just a cheesy song; it’s a real thing.

6

I have been more annoyed by cat scratches than dog bites or scratches. I was bitten in the face by a dog once (lip/chin, it swelled up, but healed, no scarring thankfully), but cat scratches make me itch. They swell like mosquito bites and feel exactly the same.

7

There are doctors all over this. They’re just not as given to speculation and curiosity as the Dopers.

I hear you about various reactions to the shots, but if the reactions to shots are allergic and local, they’re going to be local to the shot site and not the wound site.

Cat scratch fever, we know about. We’ve all had it. Not a big deal.

All sorts of other things local to the wound - yes, that’s to be expected, and we’re used to them. What seemed odd in this case was that the timing of the reaction at the wound site was associated so closely with the shots, and so long after the wound was otherwise healed and quiet.

8

This point got interesting in re whether to get the shots at all. ER doctors said no shots needed. Newspaper said health department said shots ARE needed in the event of a scratch without any bite. ER said newspaper got story wrong and called health department to demonstrate this. Health department said newspaper got story right and shots are needed. Literature packed with rabies vaccine also says scratch without bite requires shots.

I understand you are not saying the shots were inappropriate and were speaking to the relative liklihood of exposure versus other explanations for the swelling et cetera.

In fact, it was my understanding of the unliklihood that lead me to be interested in the swelling. As in, “Wow, could it really be…?”

9

Cats lick their paws a lot. Can the rabies pathogens survive for any length of time on the animal’s claws prior to scratching a person?

10

Yes, this is what is compelling for me also. The fact that the reaction was localized to the wound site, and not at the injection site, makes it unlikely to be an allergic reaction and more likely to be something related to the scratch. Such as:

  1. Something from the cat’s claw got deposited under the skin at the time of the scratch.

  2. Whatever that was didn’t in itself elicit much of an immune response; hence it was not cleared by the immune system and stayed at the wound site while the wound healed.

  3. When the anti-rabies immunoglobulin hit that substance, the immunoglobulin reacted strongly with it.

  4. That reaction elicited a strong immune response, hence the swelling, redness, etc.

It seems logical to assume that, since it was anti-rabies immunoglobulin that elicited the immune response, it was rabies virus that was deposited under the skin by the cat scratch. That could be.

But, since the immunoglobulin doesn’t need whole live virus to cause a reaction, and can also react with dead virus and/or fragments of virus, the latter may be what was deposited by the scratch or all that remained when the immunoglobulin was injected (ie. maybe a small amount of live virus was deposited by the scratch, but the small immune reaction to that and the healing process elicited by the wound broke down the virus).

Alternatively, what was deposited by the scratch could have been a nonviral substance that is commonly found with the virus and was present when the anti-rabies immunoglobulin was made.

I’d be curious to know if people who have experience giving postexposure anti-rabies immunoglobulin see this kind of reaction very often. What did your people say?