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Why do pubic lice cause intense itching in the pubic region?

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sexually transmitted disease Scanning electron micrograph of the spirochete *Treponema pallidum* attached to testicular cell membranes.

Pubic lice (Phthirus pubis), also known as crab lice, cause intense itching in the pubic region because they are bloodsucking parasites. These lice attach themselves to the base of pubic hairs to feed on the host's blood. This feeding process, along with the resulting inflammation of the skin, leads to the intense itching that typically develops two to three weeks after the initial infestation. In some cases, this persistent irritation and inflammation can result in eczema.12