Which route of entry applies to a poisoning case where a substance contacts skin directly?

In the case of poisoning where a substance contacts the skin directly, the appropriate route of entry is absorption. This occurs when a toxin penetrates into the body through the skin or mucous membranes. Substances that are absorbed can enter the bloodstream and potentially cause harm throughout the body, depending on their chemical properties and the extent of exposure.

The absorption route is particularly significant for certain chemicals that can be delivered effectively through the skin, resulting in systemic effects. Examples include poisons like organophosphates or heavy metals, which can affect the nervous system or other bodily functions.

In contrast, inhalation refers to substances entering the body through the respiratory system, injection involves substances being introduced directly into the body via a needle or similar method, and ingestion involves consuming a substance orally. Each of these routes has distinct implications and mechanisms for how toxins affect the body, but in this scenario, direct contact of a substance with the skin clearly aligns with absorption as the route of entry.