Drug-induced acneiform eruptions are a group of eruptions of papules and pustules that resemble acne. These conditions typically have an acute or subacute onset and are often more widespread than acne vulgaris.

Steroid acne can result from the use of topical, oral, or even inhaled corticosteroids. Systemic steroids may give rise to the sudden onset of follicular papules and pustules approximately 2-5 weeks after starting the medication. The chest and back are sites of predilection. Topical steroid use on the face may give rise to an acneiform eruption or rosacea. Exogenous testosterone can induce acne, and anabolic steroids can worsen preexisting acne. Acne fulminans may be an effect of each of these compounds.

An acneiform eruption (also known as papulopustular eruption) is the most common skin reaction from molecularly targeted therapies for cancer, especially epidermal growth factor receptor inhibitors (EGFRi), tyrosine kinase inhibitors (TKIs), and MEK inhibitors. It may also be seen less commonly with combination BRAF / MEKi therapy, and from mTOR inhibitors and immune checkpoint inhibitors. Lesions often occur within the first 2-4 weeks of therapy. After discontinuation of targeted therapy or exposure, lesions usually heal within 4 weeks without sequelae. The EGFR inhibitor-induced acneiform eruption is dose-dependent, with increased severity observed with greater drug exposure. Further, the better the antitumor activity of the targeted cancer therapy, the worse the skin reaction. This dose dependency has not been reported for MEK, BRAF, mTOR, or PD-1 inhibitors. In most patients, acneiform eruptions are considered mild and manageable, despite causing discomfort. Moderate and severe eruptions can occur and often lead to dose modification or treatment interruption.

Other medications commonly associated with acneiform eruptions include phenytoin, lithium, isoniazid, azathioprine, and halogenated compounds, such as bromides or iodides. The isoniazid eruption is usually mild and resolves completely after drug discontinuation. The acneiform eruption to lithium may take months to develop. A widespread papulopustular eruption is seen. Both acne conglobata and hidradenitis suppurativa have also been reported, and in severe cases, scarring after resolution may be seen.

Vitamin B6 and B12 can induce acneiform lesions, as can upadacitinib and tofacitinib. Elexacaftor / tezacaftor / ivacaftor, used in the treatment of cystic fibrosis, is associated with a new-onset acneiform eruption or worsening or recrudescence of acne. In one study, necrotizing infundibular crystalline folliculitis was observed on skin biopsy in 4 patients.