No te toques la picadura, que puede empeorar.

Because this is a negative command: No te toques...

In Spanish, negative commands use the present subjunctive, not the ordinary present tense.

• tú tocas = you touch / you are touching
• no toques = don’t touch

Since the verb is tocarse here, the full form becomes:

• no te toques = don’t touch yourself / don’t touch it on yourself

So toques is not describing what you do; it is telling someone not to do something.

Te is the reflexive pronoun for tú.

The verb here is tocarse, not just tocar.

• tocar = to touch
• tocarse = to touch oneself / to touch one’s own body

In this sentence, the person is being told not to touch the bite on their own body, so Spanish uses the reflexive pronoun:

• No toques la picadura = Don’t touch the bite
• No te toques la picadura = Don’t touch the bite on yourself / Don’t touch your bite

In practice, this reflexive version sounds very natural when talking about parts of the body or something on your body.

Spanish very often uses the definite article (el, la, los, las) instead of a possessive like my, your, his when talking about body parts or things closely connected to the body.

So instead of saying:

• tu picadura

Spanish often prefers:

• la picadura

The idea of possession is already clear from te.

This is similar to:

• Lávate las manos = Wash your hands
• Me duele la cabeza = My head hurts

So la picadura is completely natural here.

Not always, but it is very common.

Compare:

• Toca la mesa = Touch the table
• Se toca la cara = He/She touches his/her face

When the thing being touched is part of the subject’s own body, Spanish often uses a reflexive construction.

That said, context matters, and sometimes Spanish can also use a non-reflexive verb if the meaning is clear. But in everyday speech, tocarse is very normal for touching yourself.

Here que means something like because, since, or as.

• No te toques la picadura, que puede empeorar.

This structure is common in Spanish: a warning or instruction, followed by que + explanation.

It does not literally mean that here in the usual English sense. It introduces the reason for the warning.

Similar examples:

• Abrígate, que hace frío. = Put a coat on, because it’s cold.
• No salgas, que va a llover. = Don’t go out, because it’s going to rain.

It refers to la picadura.

Spanish often leaves out repeated words when they are obvious from context. So:

• la picadura puede empeorar = the bite/sting can get worse

The sentence omits the noun after que because it is understood.

So the full idea is:

• No te toques la picadura, que (la picadura) puede empeorar.

Because Spanish often omits subject pronouns when the verb form already shows who the subject is.

In No te toques, the verb form toques already tells you it is tú.

So:

• No te toques la picadura = natural
• Tú no te toques la picadura = possible, but more emphatic

Spanish usually includes tú only when it wants emphasis, contrast, or clarification.

Here it is intransitive.

• empeorar = to get worse / to worsen

In this sentence:

• puede empeorar = it can get worse

No direct object is needed.

Spanish can also use empeorar in a more transitive way in some contexts, but here it simply means that the bite itself may become worse.

Yes, if the context is already clear.

For example, if someone is clearly scratching or touching a bite, a speaker might simply say:

• No te toques.

That means something like Don’t touch it / Don’t mess with it / Don’t touch yourself there, depending on context.

Adding la picadura makes the sentence more specific and removes ambiguity.

Because with a negative command, object and reflexive pronouns go before the verb.

So:

• Tócate la picadura. = Touch the bite.
  Pronoun attached to the affirmative command
• No te toques la picadura. = Don’t touch the bite.
  Pronoun placed before the negative command

This is a general rule in Spanish:

• Lávate las manos.
• No te laves las manos aquí.

Yes, and it means something slightly different.

• tocarse = to touch
• rascarse = to scratch oneself

So:

• No te toques la picadura = Don’t touch the bite
• No te rasques la picadura = Don’t scratch the bite

If the person is scratching, rascarse is more precise. If the warning is broader, tocarse works well.

Yes, it sounds natural in Spain.

A few points make it very normal for everyday spoken Spanish:

• use of a negative tú command: No te toques
• use of the definite article with something on the body: la picadura
• use of que to introduce the reason: que puede empeorar

A speaker in Spain might also say similar things like:

• No te la toques, que se irrita.
• No te rasques, que empeora.

So the structure is very idiomatic.