Can mycophenolate (Cellcept) cause a malar rash?

Mycophenolate Mofetil and Malar Rash

Mycophenolate mofetil (MMF) does not typically cause malar rash, but it can occasionally be associated with drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) which may present with malar rash as one of its manifestations.

Drug-Induced Lupus Manifestations

While MMF is actually used to treat systemic lupus erythematosus (SLE) and its manifestations including lupus nephritis 1, it has been associated with certain dermatological side effects:

• MMF can cause various skin reactions, though malar rash is not listed among its common adverse effects 2
• Drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) has been reported with various medications and can present with malar rash in 45% of cases 3
• The British Journal of Dermatology study found that malar rash occurred significantly more frequently in drug-induced SCLE than in idiopathic SCLE (45% vs 6%) 3

Common Dermatological Side Effects of MMF

MMF is more commonly associated with other skin manifestations:

• Acne-like eruptions have been reported in SLE patients taking MMF 4
• These acne-like lesions may present as papulo-pustular and nodular skin lesions, sometimes with unusual features 4
• In some cases, these lesions were found to be associated with Staphylococcus aureus infections 4

MMF in SLE Treatment

It's important to note that MMF is actually a treatment for SLE rather than a cause of malar rash:

• MMF is recommended by the American College of Rheumatology for treatment of lupus nephritis 1
• It's used as both induction and maintenance therapy for lupus nephritis 1
• MMF has shown effectiveness in treating SLE patients who were inadequately controlled with corticosteroids, antimalarials, and other immunosuppressives 5, 6

Differential Diagnosis for Malar Rash in Patients on MMF

If a patient on MMF develops a malar rash, consider:

1. Disease flare of underlying SLE (most common)
2. Drug-induced SCLE (less common)
3. Photosensitivity reaction (MMF can increase photosensitivity)
4. Other medication effects (if patient is on multiple medications)

Management Approach

If malar rash develops in a patient taking MMF:

1. Evaluate for signs of SLE disease activity using clinical signs and laboratory tests (anti-dsDNA, complement levels) 1
2. Consider topical treatments for the rash:
   • Topical tacrolimus has shown efficacy in treating malar rash of SLE 7
   • Topical corticosteroids may be used for short periods
3. Ensure adequate photoprotection as MMF can increase photosensitivity 2
4. If the rash is suspected to be drug-induced and severe:
   • Consider temporary discontinuation of MMF
   • Consult with rheumatology before making medication changes in SLE patients

Key Takeaway

Malar rash is not a common direct side effect of MMF. In fact, MMF is often used to treat SLE manifestations including skin involvement. If a patient on MMF develops a malar rash, it's more likely to represent a flare of underlying SLE or possibly a rare drug-induced lupus-like syndrome rather than a direct effect of the medication.