W razie gdyby zdarzyło się użądlenie, wyjmij żądło.

W razie means in case of, in the event of, or if there is.

It is very common in warnings, instructions, and official language.

Examples:

• W razie pożaru zadzwoń po straż pożarną. = In case of fire, call the fire brigade.
• W razie problemów napisz do nas. = In case of problems, write to us.

A useful thing to remember: w razie is usually followed by a genitive noun:

• w razie użądlenia = in case of a sting / stinging

In your sentence, though, it is followed by a whole clause: w razie gdyby...

Yes — they overlap in meaning.

• w razie already introduces a contingency: in case of
• gdyby introduces a hypothetical condition: if / should it happen that

So W razie gdyby zdarzyło się użądlenie... is a bit like saying:

In the event that there should be a sting...

That is understandable and grammatical, but it sounds somewhat formal, instruction-like, and a little heavy stylistically.

Many speakers would simplify it to one of these:

• W razie użądlenia, wyjmij żądło.
• Gdyby doszło do użądlenia, wyjmij żądło.
• Jeśli dojdzie do użądlenia, wyjmij żądło.

So the original sentence is not impossible, but it is more elaborate than everyday speech usually needs.

This is a very common point of confusion.

In Polish, conditional / hypothetical meanings are often built with:

• by
• plus a form that looks like the past tense

So:

• gdyby zdarzyło się literally looks like if it happened
• but functionally it means if it were to happen or should it happen

This is normal Polish grammar.

Compare:

• Gdyby przyszedł, byłbym zadowolony. = If he came / were to come, I would be happy.
• Gdyby padało, zostaniemy w domu. = If it rains / should it be raining, we’ll stay home.

So the past-looking form does not necessarily refer to real past time here.

The verb is zdarzyć się, which means to happen, to occur.

So się is part of the normal dictionary form of the verb. It is not really translated separately here.

• zdarzyć się = to happen
• zdarzyło się użądlenie = a sting happened / a stinging occurred

You should learn it as one unit:

• To się zdarzyło. = It happened.
• Może się zdarzyć. = It may happen.
• Gdyby się to zdarzyło... = If that happened / were to happen...

Użądlenie is a noun meaning a sting or stinging.

It comes from the verb użądlić = to sting.

So:

• użądlenie = the event/result of being stung
• żądło = the stinger itself

In this sentence, użądlenie is the thing that happens:

• zdarzyło się użądlenie = a sting occurred

Grammatically, it is neuter singular.

That is an excellent grammar question.

You are right that w razie normally takes the genitive:

• w razie użądlenia

But in this sentence, w razie is not directly followed by the noun użądlenie. Instead, it is followed by a whole clause:

• w razie gdyby zdarzyło się użądlenie

Inside that clause, użądlenie is the subject of zdarzyło się, so it stays in the nominative:

• użądlenie = nominative singular

So compare:

1. W razie użądlenia, wyjmij żądło.
   Here użądlenia is genitive after w razie.

2. W razie gdyby zdarzyło się użądlenie, wyjmij żądło.
   Here użądlenie belongs to the clause zdarzyło się użądlenie, so it is nominative.

They are related, but they mean different things:

• użądlenie = the sting / the act of stinging
• żądło = the stinger

So the sentence says, in effect:

• if a sting occurs, remove the stinger

This distinction is very useful:

• Pszczoła zostawiła żądło. = The bee left its stinger.
• Użądlenie było bolesne. = The sting was painful.

Wyjmij is the imperative singular of wyjąć = to take out / remove.

So it is a direct command to one person:

• wyjmij = remove / take out

Because wyjąć is a perfective verb, the imperative suggests a single complete action:

• remove it fully

Related forms:

• wyjmijcie = remove it (plural / to more than one person)
• proszę wyjąć = please remove / remove (more formal instruction)
• należy wyjąć = it should be removed
• trzeba wyjąć = it is necessary to remove

So wyjmij is clear, direct, and practical.

Because żądło is a neuter singular noun, and in this case the nominative and accusative forms are the same.

So:

• nominative: żądło
• accusative: żądło

In the sentence, żądło is the direct object of wyjmij, so it is accusative — it just happens to look identical to the nominative form.

This is very common with neuter nouns in Polish.

It is understandable and grammatical, but it sounds rather formal, instructional, and somewhat wordy.

A more natural and concise version would often be:

• W razie użądlenia, wyjmij żądło.

Other natural alternatives:

• Jeśli dojdzie do użądlenia, wyjmij żądło.
• Gdyby doszło do użądlenia, wyjmij żądło.

So the original sentence is the kind of thing you might see in:

• instructions
• safety information
• formal written guidance

It is less likely in casual everyday speech.

Yes. Polish word order is fairly flexible.

For example:

• Gdyby zdarzyło się użądlenie, wyjmij żądło.
• Wyjmij żądło, gdyby zdarzyło się użądlenie.
  (possible, though less natural in this context)
• W razie użądlenia wyjmij żądło.

The original order puts the condition first, which is very common in instructions:

1. state the situation
2. then give the action

That makes it easy to process:

• if this happens... do this

Yes. The comma separates the conditional/background part from the main instruction:

• W razie gdyby zdarzyło się użądlenie,
• wyjmij żądło.

This is standard Polish punctuation when an introductory clause comes before the main clause.

So the comma works much like in English:

• If a sting occurs, remove the stinger.

Yes, and in fact many speakers would prefer a different expression.

Common alternatives include:

• gdyby doszło do użądlenia = if a sting occurred / if it came to a sting
• jeśli dojdzie do użądlenia = if a sting occurs
• w razie użądlenia = in case of a sting

These often sound a bit more idiomatic than gdyby zdarzyło się użądlenie.

So:

• zdarzyć się = happen
• dojść do = come to / occur
• w razie + genitive = in case of

All are possible, but some are stylistically smoother than others in this context.