Final answer:
The patient with impetigo on the face is most at risk for spreading the disease, as impetigo is a highly contagious bacterial skin infection. The other conditions mentioned are either not as easily spread or, in the case of psoriasis, not infectious at all.
Step-by-step explanation:
The question asks which disorder a patient with a given diagnosis is most at risk for spreading. Among the options provided—tinea pedis, impetigo, candidiasis, and psoriasis—the patient diagnosed with impetigo on the face is most at risk for spreading the disease. Impetigo is a highly contagious bacterial skin infection that can be spread to others through direct contact with lesions or indirectly through contact with contaminated objects. In contrast, tinea pedis (athlete's foot) and candidiasis are fungal infections that, while they can be spread, generally require specific conditions (like a moist environment) to do so. Psoriasis, on the other hand, is not a contagious condition at all.