Rosacea is a chronic inflammatory cutaneous disorder that affects the vasculature and pilosebaceous units of the face. Delayed and misdiagnosed rosacea in the SOC population has led to increased morbidity in this patient population. 1-3 It is characterized by facial flushing and warmth, erythema, telangiectasia, papules, and pustules. The 4 major subtypes include erythematotelangiectatic, papulopustular, phymatous, and ocular rosacea. 4 Granulomatous rosacea is considered to be a unique variant of rosacea. Until recently, rosacea was thought to predominately affect lighter-skinned individuals of Celtic and northern European origin. 5,6 A paucity of studies and case reports in the literature have contributed to the commonly held belief that rosacea occurs infrequently in patients with skin of color (SOC). 1 A PubMed search of articles indexed for MEDLINE revealed 32 results using the terms skin of color and rosacea vs 3786 using the term rosacea alone. It is possible that the nuance involved in appreciating erythema or other clinical manifestations of rosacea in SOC patients has led to underdiagnosis. Alternatively, these patients may be unaware that their symptoms represent a disease process and do not seek treatment. Many patients with darker skin will have endured rosacea for months or even years because the disease has been unrecognized or misdiagnosed. 6-8 Another factor possibly accounting for the perception that rosacea occurs infrequently in patients with SOC is misdiagnosis of rosacea as other diseases that are known to occur more commonly in the SOC population. Dermatologists should be aware that rosacea can affect SOC patients and that there are several rosacea mimickers to be considered and excluded when making the rosacea diagnosis in this patient population. To promote accurate and timely diagnosis of rosacea, we review several possible rosacea mimickers in SOC patients and highlight the distinguishing features.
Epidemiology
In 2018, a meta-analysis of published studies on rosacea estimated the global prevalence in all adults to be 5.46%.9 A multicenter study across 6 cities in Colombia identified 291 outpatients with rosacea; of them, 12.4% had either Fitzpatrick skin types IV or V.10 A study of 2743 Angolan adults with Fitzpatrick skin types V and VI reported that only 0.4% of patients had a diagnosis of rosacea.11 A Saudi study of 50 dark-skinned female patients with rosacea revealed 40% (20/50), 18% (9/50), and 42% (21/50) were Fitzpatrick skin types IV, V, and VI, respectively.12 The prevalence of rosacea in SOC patients in the United States is less defined. Data from the US National Ambulatory Medical Care Survey (1993-2010) of 31.5 million rosacea visits showed that 2% of rosacea patients were black, 2.3% were Asian or Pacific Islander, and 3.9% were Hispanic or Latino.8
Clinical Features
Each of the 4 major rosacea subtypes can present in the SOC population. The granulomatous variant has been predominantly reported in black patients.13 This predilection has been attributed to either an increased susceptibility in black patients to develop this variant or a delay in diagnosis of earlier phases of inflammatory rosacea.7
In a Saudi study (N=50), severe erythematotelangiectatic rosacea was diagnosed in 42% (21/50) of patients, with the majority having Fitzpatrick skin type IV. The severe papulopustular subtype was seen in 14% (7/50) of patients, with 20% (10/50) and 14% (7/50) having Fitzpatrick skin types IV and VI, respectively.12 In a Tunisian study (N=244), erythematotelangiectatic rosacea was seen in 12% of patients, papulopustular rosacea in 69%, phymatous rosacea in 4%, and ocular rosacea in 16%. Less frequently, the granulomatous variant was seen in 3% of patients, and steroid rosacea was noted in 12% patients.14
Recognizing the signs of rosacea may be a challenge, particularly erythema and telangiectasia. Tips for making an accurate diagnosis include use of adequate lighting, blanching of the skin (Figure 1), photography of the affected area against a dark blue background, and dermatoscopic examination.3 Furthermore, a thorough medical history, especially when evaluating the presence of facial erythema and identifying triggers, may help reach the correct diagnosis. Careful examination of the distribution of papules and pustules as well as the morphology and color of the papules in SOC patients also may provide diagnostic clues.
Figure 1. Diascopy revealed telangiectasia associated with rosacea on the central face of a woman with Fitzpatrick skin type IV. Photograph courtesy of Jennifer David, DO (Philadelphia, Pennsylvania).
Differential Diagnosis and Distinguishing Features
Several disorders are included in the differential diagnosis of rosacea and may confound a correct rosacea diagnosis, including systemic lupus erythematosus (SLE), seborrheic dermatitis, dermatomyositis, acne vulgaris, sarcoidosis, and steroid dermatitis. Many of these disorders also occur more commonly in patients with SOC; therefore, it is important to clearly distinguish these entities from rosacea in this population.
Systemic Lupus Erythematosus
Systemic lupus erythematosus is an autoimmune disease that commonly presents with erythema as well as erythematous inflammatory facial lesions similar to rosacea. The classic clinical appearance of SLE is the butterfly or malar rash, an erythematous macular eruption on the malar region of the face that also may involve the nose. This rash can appear similar to rosacea; however, the malar rash classically spares the nasolabial folds, while erythema of rosacea often involves this anatomic boundary. Although the facial erythema in both SLE and early stages of rosacea may be patchy and similar in presentation, the presence of papules and pustules rarely occurs in SLE and may help to differentiate SLE from certain variants of rosacea.15