The primary diffuse (the pure and primitive) lepromatous leprosy is a subtype of lepromatous leprosy.
Necrotic skin lesions appear rarely in lepra reactions. They are characteristic of the Lucio phenomenon which occurs in patients with diffuse lepromatous leprosy but may be seen in patients who have a severe attack of erythema nodosum leprosum or its variants, erythema multiforme leprosum and an eruption which resembles the allergic vasculitis of Ruiter.
Six cases of lepra reaction with necrotizing skin lesions are reported and their clinical features are emphasized.
Moschella SL. The Lepra Reaction With Necrotizing Skin LesionsA Report of Six Cases. Arch Dermatol. 1967;95(6):565-575. doi:10.1001/archderm.1967.01600360011002