Lucio phenomenon

Type 2 lepra reaction with vasculonecrotic phenomenon

Occurs only in the diffuse form of leprosy when no nodules appear erythematous spots appear without localized infiltrations (diffuse leprosy that never presents papules, plaques or lepromas in the course of disease) and evolve into small superficial ulcerations, generally triangular or angular, that heal leaving atrophic and hypochromic scars.

Occurs in leprosy with plaques and nodules, vasculonecrotic lesions with eschars are formed.

Occurs in untreated individuals, a few years after onset of  disease and, disappears with treatment being sometimes replaced by erythema nodosum

More frequent in the first months of treatment

Reddish 0.5 to 1.0 cm spots that ulcerate

Extensive and deep necrotic lesions, regular and round or oval ulcerations overlying a nodule.

Burning sensation

Ischemic pain

Usually afebrile, never appear to be acutely ill, except in severe cases of extensive necrosis.

Presents with fever and constitutional symptoms

Does not affect nerves

It may be accompanied by neuritis

No general symptoms or visceral damage

Arthralgia, iridocyclitis, orchitis, lymphadenopathy, nephritis, hepatitis

Positive Medina test

Negative Medina test

Histopathology shows colonization of the endothelial cell by acid fast bacilli, ischemic epidermal necrosis, necrotizing vasculitis of the small vessels of the superficial dermis, endothelial proliferation of the medium-sized vessels of the mid-dermis with passive venous congestion, and neutrophilic infiltration.

Histopathology shows panvasculitis develops. It starts in the hypodermis, where the affected vessels are of variable caliber, with larger necrosis resulting in fibrotic scars.

Does not respond to thalidomide

Responds to thalidomide

Resolution in 15 days

Slow resolution

Small hypochromic scars with hyperchromic border

Large deep ulcers result in fibrotic, hypertrophic and radiated scars