What is the treatment for a macular (macular) rash, also known as a maculopapular rash?

From the Guidelines

The most effective treatment for a macular rash, particularly in the context of immune checkpoint inhibitors, is to continue the immunotherapy and use oral antihistamines such as cetirizine/loratidine 10 mg daily and topical corticosteroids like clobetasol propionate for body and aclometasone for the face, as recommended by the Society for Immunotherapy of Cancer 1. When managing a macular rash, it's crucial to assess the severity based on the percentage of body surface area (BSA) affected and the presence of symptoms.

• For grade 1 macular rash (covering <10% BSA with or without symptoms), the management includes continuing the immune checkpoint inhibitor (ICI), oral antihistamines, and topical corticosteroids.
• For grade 2 (covering 10-30% BSA with or without symptoms), a non-urgent dermatology referral is recommended alongside continued ICI, oral antihistamines, and topical corticosteroids.
• For grade 3 (covering >30% BSA with or without symptoms), holding the ICI, same-day dermatology consultation, ruling out systemic hypersensitivity, and using oral antihistamines and systemic corticosteroids like prednisone are advised. In cases where the macular rash is due to other causes, such as swimmers’ itch/cercarial dermatitis, the treatment may involve topical corticosteroids, but the condition typically resolves spontaneously over days to weeks 1. It's essential to tailor the treatment approach based on the underlying cause of the macular rash and to consider the potential side effects and interactions of any medications used, especially in the context of immunotherapy. Key considerations include:
• The grade of the rash and its impact on the patient's quality of life and ability to perform daily activities.
• The potential for systemic involvement or hypersensitivity reactions.
• The need for specialist referral, particularly for grade 2 and 3 rashes.
• The importance of gentle skin care and avoidance of irritants to prevent further irritation.

From the FDA Drug Label

Directions for itching of skin irritation, inflammation, and rashes: adults and children 2 years of age and older: apply to affected area not more than 3 to 4 times daily

children under 2 years of age: ask a doctor

for external anal and genital itching, adults: when practical, clean the affected area with mild soap and warm water and rinse thoroughly gently dry by patting or blotting with toilet tissue or a soft cloth before applying apply to affected area not more than 3 to 4 times daily

children under 12 years of age: ask a doctor

The treatment for macular rash is to apply hydrocortisone (TOP) to the affected area not more than 3 to 4 times daily for adults and children 2 years of age and older 2. For children under 2 years of age, it is recommended to ask a doctor.

• Key considerations:
  • Apply to affected area as directed
  • Avoid contact with eyes
  • Do not use more than directed unless told to do so by a doctor
  • If condition worsens or symptoms persist, stop use and ask a doctor 2

From the Research

Macular Rash Treatment

The treatment for macular rash depends on the underlying cause of the condition.

• The diagnosis of a generalized rash, including macular rash, can be challenging due to the many different conditions that produce similar rashes 3.
• A study published in The Journal of Emergency Medicine presents an algorithmic approach to rashes, focusing on life-threatening causes of rash in each category, including maculopapular rashes 4.
• For maculopapular rashes with fever in adults, the differential diagnosis is broad and includes infectious processes, tick-borne illnesses, and hypersensitivity reactions 5.
• In terms of treatment, topical antihistamines, mast cell stabilizers, and dual-action agents are commonly used to treat allergic conjunctivitis, which can present with macular rash-like symptoms 6.
• The treatment of allergic rashes, including macular rash, may involve the use of genetic tests, in vitro tests, and biomarkers to define endotypes of atopic dermatitis 7.

Treatment Options

• Topical dual-action antihistamines/MCS, such as olopatadine, azelastine, ketotifen, and epinastine, are commonly used to treat mild forms of allergic conjunctivitis 6.
• High-concentration olopatadine has been shown to have a longer duration of action and better efficacy on ocular itch compared to low-concentration olopatadine 6.
• The use of validated in vitro tests with high sensitivity and specificity for drug allergies can help guide treatment decisions for allergic rashes, including macular rash 7.

Diagnostic Approach

• A thorough history and physical examination, followed by consideration of red flags, are essential in diagnosing and managing macular rash 4.
• The classification of rashes into morphologic groups, such as petechial/purpuric, erythematous, maculopapular, and vesiculobullous, can help guide the diagnostic approach 4.
• The presence of fever and systemic signs of illness should be assessed in patients with macular rash to determine the underlying cause and guide treatment decisions 5.