Certain drugs can induce or significantly worsen acne-like breakouts. This reaction is often termed an “acneiform eruption” because it closely resembles common acne (Acne Vulgaris) but arises as a direct side effect of a pharmaceutical agent. Drug-induced acne differs from typical acne because it is driven by the medication’s interference with the skin’s normal biology, rather than hormonal changes or bacterial overgrowth. Effective treatment requires identifying and addressing the causative medication, as the skin issue will often persist otherwise.
Medications Known to Trigger Acne
Systemic corticosteroids, such as prednisone, are frequent causes of acneiform eruptions, affecting individuals using them for conditions like asthma or autoimmune disorders. This reaction occurs with both oral tablets and high-potency topical creams.
Medications used in psychiatry and neurology also trigger acne, notably lithium (a mood stabilizer) and various anticonvulsants like carbamazepine, phenytoin, and lamotrigine. Immunosuppressants, particularly cyclosporine and azathioprine, used to prevent organ rejection or treat severe autoimmune disease, have also been implicated.
Uncommon but notable triggers include high doses of Vitamin B supplements (B6 and B12), which can cause inflammatory lesions. Anabolic-androgenic steroids, used for muscle building, are well-known to induce severe acne by powerfully stimulating the sebaceous glands. A newer class of targeted cancer drugs called Epidermal Growth Factor Receptor (EGFR) inhibitors also frequently causes a distinctive acneiform rash.
Biological Pathways Causing Drug-Induced Acne
The mechanisms by which drugs cause these eruptions are diverse and distinct from the typical acne pathway. One major route involves hormonal disruption, where medications directly affect the sebaceous glands responsible for oil production. Androgenic steroids and systemic corticosteroids, for instance, increase sebum production and alter the skin environment, leading to lesion formation.
Another key mechanism is the induction of a direct inflammatory response within the hair follicles. Drugs like lithium induce neutrophils, a type of white blood cell, resulting in folliculitis characterized by inflammatory cells. Glucocorticoids also enhance Toll-like Receptor 2 (TLR2) expression in skin cells, heightening the inflammatory reaction to common skin bacteria.
A third pathway involves the alteration of keratinization, the process by which skin cells mature and shed. Drugs such as EGFR inhibitors disrupt the normal growth of follicular cells, leading to follicular hyperkeratinization and plugging. Corticosteroid-induced acne may involve necrosis and rupture of the follicular epithelium, a process different from the abnormal keratinization characterizing typical acne.
Recognizing the Clinical Differences in Drug-Induced Acne
Distinguishing drug-induced acne from the common variety is important for proper diagnosis. A key feature of drug-induced acneiform eruptions is their sudden onset, often appearing rapidly within weeks of starting a new medication.
Unlike Acne Vulgaris, which features a mix of blackheads, whiteheads, papules, and pustules, drug-induced lesions are characteristically monomorphic. Monomorphic lesions look identical, usually presenting as small, uniform papules and pustules without the comedones typical of common acne.
These eruptions may also appear in atypical locations not usually associated with acne, such as the arms, legs, or trunk, in a uniform distribution. Furthermore, drug-induced acne can appear in older adults who have no prior history of the condition, falling outside the typical age range for acne.
Management and Treatment Approaches
The most important step in managing drug-induced acne is addressing the root cause: the offending medication. This requires consulting the prescribing physician to discuss whether the drug can be safely discontinued, substituted with an alternative, or reduced in dosage. Patients must never stop taking a prescribed medication without first speaking to their doctor, as many of these drugs treat serious or chronic conditions.
If the causative medication cannot be stopped, symptomatic treatment is initiated to manage the eruption. Standard acne therapies are employed, including topical retinoids like adapalene and antimicrobials such as benzoyl peroxide. Oral antibiotics, particularly tetracyclines (doxycycline or minocycline), may be used for inflammatory lesions. However, drug-induced acne can sometimes be resistant to conventional treatment until the underlying drug cause is addressed.