Which acne treatment should be avoided for a pregnant 15-year-old client?

Oral tetracycline hydrochloride is the treatment that should be avoided for a pregnant 15-year-old client due to its potential harmful effects on fetal development. Tetracycline is classified as a category D medication, meaning there is evidence of risk to the fetus, particularly concerning bone and teeth development. The use of tetracycline during pregnancy can lead to permanent discoloration of the teeth and may also affect bone growth in the fetus.

In contrast, topical benzoyl peroxide is generally considered safe in pregnancy due to its limited systemic absorption, while salicylic acid, particularly in topical forms and lower concentrations, is also deemed to have a lower risk compared to oral medications, though its use should still be approached with caution. Retinoids, especially in oral form, are known to have significant teratogenic effects and are avoided during pregnancy. However, that context makes the choice of tetracycline particularly critical to highlight for pregnant individuals as the primary concern revolves around its systemic effects as opposed to localized treatments.