The present invention relates to an immunologically active phyto-mixture comprising at least one plant extract selected from the family (a) Asteraceae, (b) Verbenaceae, and/or (c) Burseraceae, preferably at least one plant extract from the genus (a) Bidens, (b) Stachytarpheta, and/or (c) Bursera. Particularly preferred species include (a) Bidens alba, Bidens pilosa, (b) Stachytarpheta jamaicensis, Stachytarpheta cayennensis, Stachytarpheta indica, and/or (c) Bursera simaruba, Bursera microphylla, Bursera glabrifolia. The phyto-mixture optionally comprises (d) at least one further biologically active plant extract, such as Aloe vera and/or Stemodia maritima. The afore-mentioned phyto-mixture according to the invention exhibits good antimicrobial and anti-inflammatory efficiency and is particularly suitable for prevention and treatment of efflorescences. Therefore, the present invention also relates to a preparation for oral and topical administration for prevention and treatment of efflorescences of the skin and the mucous membrane.