Occupation-induced irritant-, immediate-, and delayed-type allergic skin reactions, as well as respiratory symptoms, are not infrequently observed in the cosmetic and especially pharmaceutical industry, where workers may have direct skin contact with irritant and sensitizing substances, such as drugs and chemically reactive intermediates. With a highly irritant and allergenic compound, one accidental exposure may cause a chemical burn, followed by primary sensitization, and allergic contact dermatitis. We will mention a few causes of immediate-type allergic reactions but will focus on delayed-type allergic reactions, i.e., allergic contact dermatitis, which can be located at the site of contact, which is generally the hands (Karagounis and Cohen 2023). However, other sites may also be involved and airborne reactions on exposed and exceptionally nonexposed areas (e.g., by particles trapped under clothing) are not uncommon. Even generalized reactions may occur due to inhalation or transcutaneous absorption. The pharmaceutical allergens described belong to many different pharmacological classes. If several cases occur in the same company, then the working conditions must be changed to prevent their recurrence. Measures to be taken include dust control and the installation of closed filter equipment and keeping the workers informed about the potential cutaneous and other risks associated with the manipulation of the chemicals likely to be contacted. Moreover, individual protective measurements—adequate protecting gloves, clothing, mask, and, if necessary, boots—followed by close monitoring of their effectiveness are also necessary. Finally, intensive educational programs might prove very useful to avoid occupational exposure.