You are correct. Meyerson nevus, a benign condition which is distinct from dysplastic nevus syndrome, occurs when a nevus triggers a halo of eczematous inflammation. However, an important consideration in the differential diagnosis is melanoma. People w/ dysplastic nevus syndrome are at higher risk of malignant melanoma; in fact, pruritus, crusting, or inflammation involving a nevus are important warning signs for melanoma and should prompt an urgent consultation. In this case, however, the inflammation resolved w/ topical steroid tx, and melanoma was ruled out.

You are correct. Paroxysmal finger hematoma, or Achenbach syndrome, is a rare, self-limiting condition of unknown etiology. Hematological and radiological investigations are often normal, and diagnosis is made on clinical grounds. The condition remits spontaneously, and no specific tx is needed. Recognition of Achenbach syndrome should prevent extensive unnecessary investigations.