Determining the source of redness helps set management and patient-education strategies. A treatment that targets lesions, for example, may have minimal effect on persistent erythema or telangiectasias. Conversely, a treatment only targeting to diffuse erythema may create the perception that lesions have worsened, when, in fact, reducing background redness makes the lesions stand out more.
Regarding differential diagnosis, factors that can help distinguish lesional rosacea from acne vulgaris include the presence of telangiectasias and eye symptoms, and absence of comedones, with rosacea. Regarding primarily erythematous presentations, pustules rarely occur in the malar rash of lupus, while the characteristic lesions of discoid lupus are coin-like, red and scaly, appearing on the cheeks, nose, ears and scalp.
Red, scaly lupus lesions may also resemble those of seborrheic dermatitis. “On dermoscopy,” write Johnson et al., “rosacea has linear vessels arranged in a polygonal network, while seborrheic dermatitis has dotted vessels in a patchy distribution.” Miscellaneous rosacea mimics can include erythrodermic psoriasis, pustular psoriasis, impetigo and erysipelas.
For the past decade, treatment decisions have been driven by rosacea subtype classification. However, experts now advise a phenotype-based approach, which allows better treatment targeting. The growing array of therapies allows increasing individualization, study authors add.
For papules and pustules, topical treatments include metronidazole 0.75% cream, ivermectin 1% cream, azelaic acid 15% gel and foam and sodium sulfacetamide 10% with or without sulfur. Topical treatments that target erythema include brimonidine 0.33% gel and oxymetazoline 1% cream. Commonly used oral treatments for rosacea include tetracycline-type agents in antibiotic and subantimicrobial doses.
Dr. Johnson is or has been a consultant, speaker and investigator for Galderma.
1. Johnson SM, Berg A, Barr C. Recognizing rosacea: tips on differential diagnosis. J Drugs Dermatol. 2019;18:888-894.
2. Alexis AF. Rosacea in patients with skin of color: uncommon but not rare. Cutis. 2010;86:60-62.
3. Gold LS, Papp K, Lynde C, et al. Treatment of rosacea with concomitant use of topical ivermectin 1% cream and brimonidine 0.33% gel: a randomized, vehicle-controlled study. J Drugs Dermatol. 2017;16:909-916.
4. Webster G, Schaller M, Tan J, et al. Defining treatment success in rosacea as “clear” may provide multiple patient benefits: results of a pooled analysis. J Der- matol Treat. 2017;28:469-474.