The correct answer is B. Erythema elevatum diutinum.

This clinical vignette along with the kodachrome pictured describes erythema elevatum diutinum (B), which is a chronic form of vasculitis that can be associated with infections, autoimmune connective tissue disease and IgA monoclonal gammopathies. Dapsone therapy is usually an effective treatment for this diagnosis.

Erythema induratum (A) is a lobular panniculitis that represents a cutaneous immune reaction to tuberculosis and classically presents as subcutaneous nodules that may ulcerate on the posterior calves. Erythema nodosum (C) is a septal panniculitis that commonly occurs following infections and presents as nodules on the shins. Erythema annulare centrifigum (D) is a figurate erythema that presents with annular, polycyclic erythematous plaques; it is primarily thought to be idiopathic in nature but can be reactive to an infectious etiology such as a fungal infection. Erythema dyschromicum perstans (E) characterized by oval shaped grey to brown macules and patches commonly on the face, neck and proximal upper extremities.

References: Bolognia, J. L., Schaffer, J. V., Duncan, K. O., & Ko, C. J. (2021). Dermatology essentials (2nd ed.). Elsevier.