Can hydroxychloroquine cause skin rash?: Understanding the Risks and Symptoms

October 8, 2025 •

4 min read

According to adverse event reporting, skin rashes are among the most common dermatologic reactions experienced by some patients taking hydroxychloroquine. Therefore, the answer to the question, 'Can hydroxychloroquine cause skin rash?' is yes, though the reaction can vary significantly in type and severity.

Quick Summary

Hydroxychloroquine is known to cause various skin rashes, which can range from mild and itchy to rare but severe and life-threatening conditions. Onset typically occurs within weeks of starting the medication, and symptoms often resolve after discontinuation, but careful monitoring and medical consultation are essential.

Key Points

Common Adverse Effect: Hydroxychloroquine is known to cause skin rashes in some patients, though the reaction can vary widely in severity.
Reaction Timing: Rashes typically appear within the first four weeks of starting the medication but can occur at any point during treatment.
Variety of Rashes: Reactions range from common, mild, itchy, red, bumpy rashes to rarer but more serious conditions like Acute Generalized Exanthematous Pustulosis (AGEP) and Stevens-Johnson Syndrome (SJS).
Urgent Medical Care: Blistering, peeling skin, fever, or swelling of the face, lips, or tongue are signs of a severe reaction and require immediate medical attention.
Management: For mild cases, your doctor may recommend antihistamines or topical steroids. The rash often resolves after discontinuing the drug.
Photo-sensitivity: HCQ can increase skin's sensitivity to the sun, making sun protection essential while on this medication.

The Link Between Hydroxychloroquine and Skin Reactions

Hydroxychloroquine (HCQ), also known by the brand name Plaquenil, is a disease-modifying anti-rheumatic drug (DMARD) widely used to treat autoimmune diseases like systemic lupus erythematosus (SLE) and rheumatoid arthritis. While generally well-tolerated, it is known to cause a range of adverse dermatologic effects, with rashes being a significant and frequent complication. These skin reactions result from the drug's immunomodulatory properties and can manifest as common, mild eruptions or, in rare cases, as severe, life-threatening conditions. Patients should be aware of these potential side effects and understand the importance of early recognition and appropriate management.

How Hydroxychloroquine Causes Skin Rashes

Though the exact mechanism behind HCQ-induced rashes is not fully understood, it is not typically an IgE-mediated allergic reaction. Instead, it is believed to involve a complex immune response. The drug modulates the immune system by inhibiting Toll-like receptors, which play a significant role in inflammatory processes. In some individuals, this can trigger an immune-mediated hypersensitivity response that presents on the skin. The potential for phototoxicity, where the drug increases skin sensitivity to sunlight, can also trigger or worsen a rash. Given HCQ's long half-life, any induced reactions can persist for several weeks after discontinuing the medication.

Types of Hydroxychloroquine-Induced Rashes

HCQ can cause a variety of skin reactions. The most common type is a mild, generalized drug eruption, but more serious, though rare, reactions are possible.

Morbilliform or Exanthematous Drug Eruption: This is the most common type of rash associated with HCQ. It appears as a red, bumpy, and often itchy rash across the body. It can be difficult to distinguish from a viral rash or an underlying condition flare-up.
Urticaria (Hives): Raised, itchy welts (hives) may also appear, sometimes with associated swelling. In rare cases, swelling of the face, lips, or tongue can signal a severe allergic reaction.
Photosensitivity: HCQ can increase sensitivity to sun exposure, leading to an exaggerated sunburn-like reaction on sun-exposed areas.
Hyperpigmentation: Long-term HCQ use can cause a blue-gray or black discoloration of the skin, nails, and inside of the mouth, particularly in areas of bruising.
Serious Skin Reactions: Though rare, HCQ can cause life-threatening skin reactions such as:
- Acute Generalized Exanthematous Pustulosis (AGEP): Characterized by widespread, small, pus-filled pustules on a red, scaly background, often with fever.
- Stevens-Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN): A severe reaction causing blistering and peeling of the skin, often accompanied by fever and flu-like symptoms.
- Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): A severe drug eruption that includes a widespread rash, fever, swollen lymph nodes, and involvement of internal organs.

What to Do If You Develop a Rash

If a rash appears, it is crucial to consult your healthcare provider promptly. They can determine if the rash is related to the medication, a flare-up of your condition, or another issue entirely.

For a mild rash:

Contact your doctor immediately, but follow their instructions. They may recommend over-the-counter antihistamines like cetirizine or topical corticosteroids to relieve itching and inflammation.
Avoid scratching the affected area.
Protect your skin from the sun by wearing protective clothing and using sunscreen.
Use unperfumed moisturizers regularly to soothe irritated skin.

For a severe reaction, seek immediate medical attention if you experience:

Blistering or peeling of the skin, including inside the mouth.
Fever and flu-like symptoms with a rash.
Widespread, painful, or pus-filled spots.
Swelling of the face, lips, tongue, or throat.

Hydroxychloroquine Rash vs. Lupus Rash

Distinguishing between a drug-induced rash and a flare-up of an underlying condition like lupus can be challenging. A physician will consider timing, pattern, and other symptoms to make a diagnosis.


Characteristic	Hydroxychloroquine Drug Rash	Lupus Rash (e.g., Subacute Cutaneous Lupus)
Onset	Typically within 4 weeks of starting or changing dosage.	Can appear at any time, often triggered by sun exposure.
Appearance	Often a generalized, red, itchy, bumpy rash (morbilliform) or hives.	Can be widespread, scaly, or appear as characteristic butterfly rash on the face.
Symptom Profile	Accompanied by itching. Severe reactions may include fever and other systemic symptoms.	Accompanied by other lupus symptoms like joint pain, fatigue, and fever.
Response to Treatment	Often resolves after discontinuing HCQ.	Requires treating the underlying lupus flare, potentially with HCQ or other medications.
Biopsy	Can show interface dermatitis and dermal eosinophils.	Shows interface dermatitis without eosinophils.

Conclusion

While generally considered safe, hydroxychloroquine can cause skin rashes as a common side effect, with some reactions being rare and severe. Patients taking HCQ for autoimmune conditions like lupus or rheumatoid arthritis should be vigilant for any dermatologic changes. Timely communication with your healthcare provider is crucial, as mild cases can often be managed with supportive measures, while severe reactions require immediate cessation of the drug and emergency medical care. The decision to manage or discontinue HCQ should always be made in consultation with a physician, weighing the benefits of the treatment against the potential risks of side effects. For more detailed information on HCQ's dermatologic effects, the National Institutes of Health provides a resource on adverse events, including those related to the skin.

Frequently Asked Questions

Skin rashes are a relatively common side effect of hydroxychloroquine. Data from adverse event reporting indicates that drug rashes or hypersensitivity reactions were the most common dermatologic issue reported, though the severity varies greatly.

A typical rash is often described as a red, bumpy (morbilliform) eruption that can be itchy. It can appear on one part of the body or spread across the entire body.

Rashes typically occur within the first few weeks, often within four weeks, of beginning hydroxychloroquine treatment. However, reactions can sometimes have a delayed onset.

You should not stop your medication without consulting your doctor. If the rash is mild, they may advise continued use with supportive care. If it is severe, they will likely have you stop the drug.

For mild rashes, your healthcare provider may suggest a mild topical steroid cream or an unperfumed moisturizer. They may also recommend oral antihistamines to help with itching.

A dermatologist can help differentiate. A hydroxychloroquine rash often has dermal eosinophils on biopsy, while a lupus rash typically does not. The timing of onset and other accompanying symptoms also provide clues to the cause.

Yes, hydroxychloroquine can cause photosensitivity, which increases your skin's sensitivity to the sun. This can worsen an existing rash or trigger a new one in sun-exposed areas.