Livedo reticularis, a netlike erythema with fine, regular, and complete (“closed”) meshes, which is more common and generally physiological.

Livedo racemosa with large, sometimes broken meshes, which is always pathological and characteristic of Sneddon’s syndrome, for example.

Infiltrated, palpable livedo associated with sometimes purpuric papules, plaques, or nodules, mainly observed in vasculitis, such as polyarteritis nodosa (cf. Fig. 15.​32).

Purpuric livedo or retiform purpura which is indicative of a thrombotic vasculopathy involving the dermal ­vessels with muscular walls (cf. Figs. 14.​13, 14.​14, and 14.​15); this type of livedo can be seen, for example, in disseminated intravascular coagulation or in catastrophic antiphospholipid antibody syndrome. The key significance of this livedo is discussed in Chap.​ 14.