Characterizing cutaneous manifestations of systemic autoimmune rheumatologic diseases in Filipino skin

Cutaneous findings provide important clues to systemic autoimmune rheumatologic diseases (SARDs), but presentation varies across skin types and may be underrecognized in patients of color. In the Philippines, diagnostic challenges are amplified by limited specialists and a lack of pigmented-skin learning materials for general practitioners.

To develop online educational resources on cutaneous manifestations of SARDs in Filipino skin (phases 1 and 2a), and characterize the demographic and clinical profile of these patients (phase 2b).

Phase 1 videos were created and posted online for sharing. Phase 2 was a single-center cross-sectional descriptive study that included consenting adult Filipinos at least 18 years old who presented with the above-mentioned SARDs and skin lesions in the Philippine General Hospital's Dermatology and Rheumatology outpatient clinics from August 2021 to August 2022. Demographic, medical data, and deidentified photographic images of characteristic lesions were captured. Investigators described the observed differences in the skin disease presentation of Filipino skin. Descriptive statistics were applied.

Forty-six Filipinos, 85% being female, with a mean age of 39.1 years, participated in our study. The majority (48%) had a primary diagnosis of systemic lupus erythematosus, followed by psoriasis (26%). Most (96.6%) were on immunomodulators and 57% on glucocorticoids. Three (7%) were on biologic medications. Notable differences of lesions between Filipino and Caucasian skin include the former being: (a) dark red, purple or dark brown instead of pink and bright erythema; (b) masked by pigmentation or the "blending" phenomenon; (c) more marked in contrast between hyper- and hypopigmentation; (d) more gray and black psoriatic plaques; resembling purpuric dermatoses; and (e) with blurring of skin tautness and edema in those with systemic sclerosis. There are no significant differences observed in the areas of affectation.

Phase 2 was limited by the pandemic and methodological constraints, highlighting the need for further research on cutaneous manifestations of rheumatologic diseases in Filipinos.

There are differences in lesion morphology, pigmentation, and scarring, but not in areas of affectation, in the darker skin of Filipinos with SARD. Collaboration between dermatologists and rheumatologists is essential for the effective management of these patients.