Grade 3= severe pain requiring analgesics (or narcotic analgesics for ≤ 72 hours) and/ or limiting usual activities; Grade 4= severe pain requiring hospitalisation or prolongation of hospitalisation, resulting in death, or persistent or significant disability/ incapacity, or life- threatening, or medically significant. c Grade 3= ≥ 50 mm but < 85 mm average diameter; Grade 4= ≥ 85 mm average diameter. d Grade 3= ≥ 25 mm but< 50 mm average diameter; Grade 4= ≥ 50 mm average diameter. e Grade 3= ≥ 3 cm; Grade 4= If draining. f Grade 3= refractory to topical treatment or requiring oral or parenteral treatment; Grade 4= not defined. g Grade 3= > 3 cm but ≤ 5 cm; Grade 4= > 5 cm.