This condition is defined by a ring of depigmentation specifically surrounding a central mole, a morphology not seen in the other conditions.
This fungal infection presents as scaly, confluent patches that are positive on a KOH prep, unlike the non-scaly, discrete macules of benign guttate hypomelanosis.
This is distinguished by a history of a preceding inflammatory skin condition (like eczema) in the area where the hypopigmentation now exists.
Vitiligo typically forms larger, coalescing patches of complete depigmentation (chalk-white), whereas benign guttate hypomelanosis consists of small, discrete, "sprinkled-on" macules of hypopigmentation.
This condition is characterized by atrophic, "porcelain-white" plaques, often with associated pruritus and scarring, a different texture and symptomatology.