Jessner benign lymphocytic infiltrate, or Jessner lymphocytic infiltration of the skin (JLIS), is a dermal infiltrate of lymphocytes that was characterized by Jessner and Kanoff in 1953. Clinically, there are one or more asymptomatic erythematous papules or plaques, often with an annular configuration on the face, neck, and sometimes the upper trunk. JLIS typically occurs in adults in their 30s and 40s and is quite rare in children. The disease waxes and wanes in severity over time. Some patients worsen in winter, and sunlight may exacerbate the disease in others. Individual lesions tend to resolve over weeks to months, and the cutaneous manifestations of JLIS tend to resolve over years. There is no systemic involvement.

The etiology and pathophysiology of JLIS are not well understood. Rare associations, such as medication intake (angiotensin-converting enzyme inhibitors and glatiramer acetate) and infections (Borrelia burgdorferi in Europe) have been noted.

Currently, the status of JLIS as a separate entity is questioned by many authors. Some cases have been thought to represent tumid lupus, others a form of polymorphous light eruption, and others classified as a pseudolymphoma. These diagnoses need to be entertained and ruled out first.