Follicular mucinosis can be a primary idiopathic disease or a secondary disease associated with lymphoma. When it appears in childhood or adolescence, it is usually primary and self-limited. We describe four cases of follicular mucinosis occurring in early adulthood that have had protracted courses. Each presented as an unusual acneiform eruption. Two of the cases demonstrated a clonal genetic rearrangement of the T-cell receptor within the cutaneous lymphoid infiltrate, a finding not previously reported. Although its significance is not clear, the clonal lymphocytic expansion indicates a need for continued surveillance of these patients.