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Side Effect Management

Medication-Induced Rash

October 22, 2025

Medication-Induced Rash

Rashes and Psychotropic Medications
Rash can occur with any medication. Of particular concern is the possibility of serious rash, such as Stevens-Johnson syndrome (SJS). Proper clinical management when prescribing medications involves taking steps to minimize the risk of rash, knowing how to distinguish between benign and serious rash, and knowing what to do if serious rash occurs.
Rashes	Medication	Treatment
Acne	Lithium	Standard acne treatments
Hives or urticaria	Any drug	Antihistamines
Psoriasis	Lithium	Topical steroids, vitamin D cream, topical retinoids, salicylic acid, coal tar, UV light, psoralen plus UV A
Purpura	Carbamazepine	Drug discontinuation; treatment of underlying disorder
Seborrhea	Divalproex	Medicated shampoos, topical antifungals, topical steroids
Stevens-Johnson syndrome	Bupropion, carbamazepine, chlorpromazine, divalproex, lamotrigine, venlafaxine, zonisamide	Cessation of causal agent, systemic steroids sometimes administered early in course of illness; monitoring of electrolytes, avoidance of suprainfections or sepsis

Clinical Distinctions Between Benign Rash and Serious Rash
Benign Rash	Serious Rash (occurs in less than 1% of patients)
Peaks within days, settles in 10–14 days Spotty, nonconfluent, nontender Has no systemic features, laboratory tests are normal	Confluent and widespread, or purpuric or tender Any prominent involvement of neck or upper trunk Any involvement of eyes, lips, mouth, etc. Any associated fever, malaise, pharyngitis, anorexia, or lymphadenopathy Abnormal laboratory tests for complete blood count, liver function, urea, creatinine

Minimizing the Risk of Rash
Do not start within 2 weeks of a viral infection, rash, or vaccination
Avoid new medications, foods, or products during the first 3 months to decrease the risk of unrelated rash
Patient should report any symptoms of hypersensitivity immediately (fever; flu-like symptoms; rash; any blisters; swelling of eyelids, conjunctivitis, lymphadenopathy)

What If a Rash Develops?
Ask patient about timing of rash, all medications/doses being taken, any changes in dose or adherence, and any novel environmental exposures
True drug rashes are commonly on the trunk, exanthematous (eruptive), and morbilliform (measles-like in appearance)
Rashes that occur within the first 5 days or after 8–12 weeks of treatment are rarely drug-related (for late-emerging rash, consider the possibility of formulation substitution)
Urticarial wheal-and-flare rash (vaccine) is a probable allergic reaction—assess for other potentially serious manifestations of impending anaphylaxis
Rash with Benign Characteristics	Rash with Serious Characteristics
Reduce medication dose or stop dosage increase	Stop medication (for lamotrigine, also stop valproate if administered)
Warn patient to stop drug and contact prescriber if rash worsens or new symptoms emerge	Monitor and investigate organ involvement (hepatic, renal, hematologic)
Prescribe antihistamine and/or topical corticosteroid for pruritis	Patient may require hospitalization
Monitor patient closely	Monitor patient very closely

Is Rechallenge an Option After Rash?
For benign rash that resolves after drug cessation: Yes

Related Practice Resources
	Article Mountains or Mole Hills? How to Effectively Manage Medication-Induced Rash
	Patient Education Medication Guides

Adapted from NEI Prescribe. Copyright © Neuroscience Education Institute. The information in this site is constantly subject to scientific research and information may change.

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