Clindamycin is a widely prescribed antibiotic used to treat various bacterial infections, especially in patients with penicillin allergies. Like many medications, clindamycin can cause adverse reactions, with a skin rash being one of the most frequently reported side effects. When a rash appears, it is important to understand what a clindamycin-related rash typically looks like and how to distinguish a common reaction from a severe one.
Appearance of Common Clindamycin Rashes
The most common skin reaction to clindamycin is a delayed maculopapular rash, also known as a morbilliform eruption. This rash appears as flat, red patches mixed with small, slightly raised bumps, creating a measles-like appearance. The texture is generally fine, may feel somewhat rough, and the eruption is often itchy.
This common rash is typically symmetrical, appearing on both sides of the body, and can become widespread. While maculopapular rash is the most frequent reaction, clindamycin can also cause urticaria, or hives. Mild urticaria presents as raised, intensely itchy welts with clearly defined borders that can appear anywhere.
Urticarial lesions are often intensely itchy (pruritic) and may blanch, or temporarily turn white, when pressure is applied. These common skin reactions are generally manageable but still signify an immune response to the medication. Recognizing the morphology of these rashes is the first step in determining the appropriate response.
Recognizing Signs of Severe Drug Reactions
Although rare, clindamycin has been associated with severe, life-threatening hypersensitivity syndromes requiring immediate medical attention. These reactions include Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). SJS/TEN onset is often preceded by flu-like symptoms, such as fever, chills, and muscle aches, followed by a painful red or purple rash.
The rash of SJS/TEN rapidly progresses to blistering and peeling of the skin, resembling a severe burn. A telltale sign is the development of target lesions, which look like a bull’s-eye, and widespread involvement of mucous membranes (mouth, eyes, nose, and genitals). DRESS syndrome typically presents with a widespread rash, high fever, and noticeable swelling of the face and lymph nodes.
DRESS involves systemic symptoms and internal organ injury, such as hepatitis or kidney problems, which can manifest weeks after starting the drug. Any skin reaction that includes blistering, peeling, mucous membrane erosion, or facial swelling must be treated as a medical emergency.
Contextualizing the Rash
The timing of a rash’s onset provides important context about its cause and severity. The common maculopapular rash is a delayed hypersensitivity reaction, typically appearing seven to ten days after starting clindamycin. This delayed reaction can sometimes occur earlier, or even up to eight weeks after the medication has been stopped.
The rash often begins on the trunk (chest or back) before spreading to the limbs. While severe reactions are rare, a simple maculopapular rash can sometimes be accompanied by non-severe constitutional symptoms. These might include a mild fever or general feeling of malaise, which must be clearly differentiated from the high fever and severe systemic symptoms seen in SJS/TEN or DRESS.
Action Steps and Medical Guidance
Action steps depend entirely on the visual appearance and associated symptoms of the rash. For a mild rash—such as a simple, itchy maculopapular eruption or minor hives without systemic symptoms—the prescribing physician should be contacted immediately. It is important not to stop taking the antibiotic without medical advice, as discontinuing the medication prematurely could worsen the infection being treated. Management of mild reactions often involves symptomatic relief, such as an antihistamine or, in some cases, a topical steroid.
If the rash is accompanied by any signs of a severe reaction, such as blistering, peeling skin, difficulty breathing, or swelling of the face, mouth, or throat, the drug must be stopped immediately. These symptoms indicate a medical emergency, and the patient should seek immediate care by calling emergency services or going to the nearest emergency room. Documenting the reaction, including taking photographs and noting the exact time of onset, is important for future medical reference.