Evers AW, Verhoeven EW, Kraaimaat FW, de Jong EM, de Brouwer SJ, Schalkwijk J, Sweep FC, van de Kerkhof PC. How stress gets under the skin: cortisol and stress reactivity in psoriasis. Br J Dermatol. 2010 Nov;163(5):986–91. doi: 10.1111/j.1365-2133.2010.09984.x. PMID: 20716227.