Recognizing Rosacea: Tips on Differential Diagnosis

September 2019 | Volume 18 | Issue 9 | Original Article | 888 | Copyright © September 2019

Sandra Marchese Johnson MD FAAD,a Andrew Berg PA,b Chelsea Barr MPAS PA-Cc

ªJohnson Dermatology, Fort Smith, AR

BBerg Consulting and Investments, Inc, Lee’s Summit, MO

cHouston Skin Associates, Houston, TX

lower rate of diagnosis in dark skinned individuals may include difficulty in identifying redness in more pigmented skin, lower genetic propensity to rosacea, or the ability of melanin to protect against ultraviolet light as a trigger of rosacea. In one of the few articles about rosacea in skin of color in the current literature, Alexis reports that rosacea in darker skinned individuals (Fitzpatrick types IV to VI) often presents in women previously diagnosed with late-onset acne even if these women did not have acne in their second through fourth decade of life.14 Further, he notes that many of the women have sensitive skin, react with burning or stinging to skin care products, and may have sensations of facial warmth (with or without visible flushing) in response to known rosacea trigger factors.14 Similar to the clinical presentation in lighter skinned individuals, dark skinned patients may have papules and/or pustules clustered in the central facial region, with erythema of varying severity.14 The erythema may be more difficult to appreciate in a person with a darker skin tone. Patients may be very frustrated after treating their disease with multiple acne therapies, since many have experienced skin irritation with topical acne treatments. In diagnosing rosacea in skin of color, Alexis reports “erythema may be difficult to appreciate and telangiectasias usually are not observed in highly pigmented skin.” As a result, he suggests that gathering an understanding of “a history of exacerbating factors, sensitivity to multiple topical products, episodic warmth of the face (or flushing), and ocular symptoms is especially helpful in establishing the diagnosis.”14Taylor et al add that examining skin with a bright light and microscope slide to detect blanching can help clinicians see faint erythema.15

The psychosocial impact of rosacea and negative effects on emotional health and quality of life are often under-appreciated by clinicians.10 The signs of rosacea (redness, telangiectasias) can be interpreted by lay persons as signs of excessive alcohol consumption, leading to stigmatization that exacerbates emotional distress.10

The Diverse Sources of Redness in Rosacea
Rosacea is characterized by redness, but it is very important – particularly in designing management strategies – for the clinician to be aware that there are differing sources of skin redness.11,16 Identifying the redness source will help target treatment options and patient education. Figure 3 illustrates how a patient may have various causes of facial erythema—they may have persistent erythema without a lesional aspect, erythema plus inflammatory lesions, perilesional erythema, or redness due to permanent blood vessel dilation and neoangiogenesis. Transient erythema may also occur. These different sources of redness require different treatments, and patients should be educated about what to expect with a specific treatment. For example, a treatment that targets lesions may have little to no effect on persistent erythema or telangiectasias. On the other hand, a treatment that targets only diffuse erythema may give the perception that the lesions have become worse or more red, when simply the camouflage of the background redness has disappeared making the lesions stand out more.

Trigger Factors in Rosacea
Patients with rosacea often indicate that certain factors trigger exacerbations; Table 1 presents the most common rosacea triggers according to a recent survey by the National Rosacea Society.17 It can be useful for patients to keep a diary to identify triggers that should be avoided; diaries are available at www.

Step 2 in Recognizing Rosacea: Differential Diagnosis
Distinguishing between rosacea and other conditions can be challenging, particularly since the specific facial and ocular