Table 4.

Efficacy of systemic therapies in scalp psoriasis and considerations for psoriatic alopecia

Treatment	Efficacy in scalp psoriasis	Considerations for psoriatic alopecia
TNFi	Adalimumab, infliximab: ∼92% PSSI75 at 48 weeks [68, 69]	May induce alopecia (TiAPA), occurring in ∼5% of TNFi users [72]. Discontinuation often leads to improvement [41, 45, 53, 56]
IL-17 inhibitors (brodalumab, secukinumab, ixekizumab)	Brodalumab: 89% PSSI75, 63.4% PSSI100 at 12 weeks [75]. Ixekizumab: 74.6% PSSI100 [76]	Effective for scalp psoriasis, but role in TiAPA is unclear. Common side effects: nasopharyngitis, folliculitis [64, 75, 76]
IL-23 inhibitors (guselkumab, risankizumab, mirikizumab)	Guselkumab: 85% achieving ss-IGA 0/1, outperforming adalimumab [64]. Risankizumab: 97.6% achieving sc-PGA 0/1 at 52 weeks [78]	Potential alternative for TiAPA. Some patients transitioning from TNFi to IL-23 inhibitors show favorable responses [41, 45, 53, 56]
IL-12/23 inhibitor (ustekinumab)	97.5% achieved PSSI75 in 48 weeks [68]	Patients switching from TNFi to ustekinumab for TiAPA showed improvement, but it is unclear if this was due to TNFi discontinuation or ustekinumab efficacy [41, 45, 53, 56]
PDE-4 inhibitors (apremilast)	38.4%–46.5% achieved scPGA 0/1 within 16 weeks [80–83]	Effective for scalp psoriasis, but the role in scalp psoriasis is unclear

TNFi, tumor necrosis factor inhibitors; TiAPA, TNF-α inhibitor-associated psoriatic alopecia; PSSI, psoriasis scalp severity index; PGA, physician’s global assessment.