The protozoa are single celled organisms of great medical importance.

Visit: Cutaneous Infections and Infestations

I Amebae: Amebae are single celled organisms with trophozoite and cyst stages in the life cycle.

Amebiasis

Acanthamebiasis Pustular, chronic ulcerating nodular lesions are present in the skin. Histologically, there is a dense acute inflammatory infiltrate with focal abscess formation   together with numerous organisms (amoebae ,15-40 micrometer in width). Tuberculoid  granulomatous lesion together with vasculitis may be present in the deep dermis and subcutis.

II Flagellates: The flagellates are a group of protozoa that moves by flagella.

Trypanosomiasis:

      African Trypanosomiasis

      American Trypanosomiasis

Leishmaniasis

      Cutaneous leishmaniasis

      Mucocutaneous leishmaniasis

      Visceral leishmaniasis

Giardiasis

III Coccidia: Coccidia are important in immunocompromised patients , have asexual and sexual cycles, and are acquired from contaminated food or water.

Toxoplasmosis

IV Miscellaneous

Pneumocystosis : Cutaneous pneumocystosis is rarely noted in patients with AIDS (Visit: Cutaneous lesion associated  with AIDS). There are foamy, amphophilic material around blood vessels. Methenamine silver stain reveals small cysts characteristic of Pneumocystis carinii.