Psoriasis and Psoriatic Arthritis

Modern evidence positions psoriasis and psoriatic arthritis as expressions of a single psoriatic disease spectrum, unified by dysregulated IL‑23/IL‑17 and TNF pathways and amplified by metabolic inflammation. Genetics shape phenotype: HLA‑C*06:02 often tilts toward skin-dominant disease, whereas HLA‑B27/B38/B39 and TRAF3IP2 are enriched in PsA and axial patterns. The enthesis—where tendons and ligaments insert into bone—is a critical nexus; repetitive microtrauma at this interface may trigger cytokine cascades in genetically primed individuals, explaining the tight links among nail disease, DIP arthritis, and enthesitis. Epidemiologically, roughly a quarter of patients with psoriasis develop PsA, usually after years of cutaneous disease, though subclinical synovio‑entheseal inflammation may be present earlier on ultrasound or MRI. Clinically, proactive screening in dermatology using brief tools (PEST, ToPAS, PASE) reduces diagnostic delay and enables early rheumatology referral. Treat‑to‑target strategies aiming for minimal disease activity prevent structural damage and improve function. Therapeutic selection is domain-driven: TNF or IL‑17 inhibitors are preferred for axial disease and severe enthesitis/dactylitis; IL‑23 inhibitors and ustekinumab are excellent for skin and peripheral arthritis; JAK inhibitors are potent oral options for refractory PsA. Methotrexate remains useful—particularly for skin and peripheral arthritis—and as a background agent with biologics; apremilast offers a safer oral alternative with modest efficacy. Phototherapy is valuable for skin but not joints. Across all patients, aggressive cardiometabolic risk management, weight loss, smoking cessation, and structured exercise are essential, improving disease control and reducing excess cardiovascular events that disproportionately affect psoriatic disease.

Traditional Chinese Medicine interprets psoriatic disease through patterns reflecting the interaction of heat, dampness, wind, dryness, and blood dynamics. Early erythematous plaques with active inflammation are often viewed as blood‑heat; evolution to thick, scaly, persistent plaques and nail dystrophy reflects dryness and blood stasis. Painful, swollen, warm joints typify damp‑heat Bi obstructing the channels, whereas chronic stiffness may reflect residual cold‑damp with stasis. Therapeutic aims are to clear heat, resolve damp, nourish and move blood, and free the collaterals to reconnect skin and joints within a holistic framework. Practice commonly combines internal herbal formulas with external therapies and acupuncture. For blood‑heat and damp‑heat, formulas inspired by Xiao Feng San with additions such as Sheng Di Huang, Mu Dan Pi, and Zi Cao seek to cool blood and reduce inflammation; for blood stasis and dryness, agents like Dan Shen and Chuan Xiong promote circulation. Topical indigo naturalis (Qing Dai) has randomized evidence for plaque improvement, while systemic Tripterygium wilfordii extracts have demonstrated anti‑inflammatory benefits in inflammatory arthritis but carry significant toxicity that restricts use. Acupuncture at points such as LI11, SP10, BL17 (skin) and ST36, GB34 with local points (pain/enthesitis) may relieve pain and improve function, and mind‑body practices (qigong, tai chi) support stress modulation. Within an integrative plan, TCM modalities can complement biomedical care—particularly for symptom control and quality of life—provided they are individualized, safety‑monitored, and coordinated with dermatology and rheumatology to avoid herb–drug interactions and to ensure timely escalation when joint inflammation threatens structural integrity.