I guess visually it does seem to resemble the 5 of Pentacles, what with the crippled man walking in his crutches and the other one seeming to be begging. It does exemplify the themes of privation, hardship, and lack of the 5 of Pentacles, but the idea behind the leprosarium seems sterner and much more harsh. The 5 of P does not indicate stark hopelessness - in other interpretations this want even asks the querent to meditate on his present state and to still think of all his blessings, to perhaps use whatever meager advantages he has to get back on his feet. Specially with auspicious surroundjng cards, it does not have to be all gloomy. In the Middle Ages though, leprosy could not be treated, so aside from the debilitating disease he could very well be locked in this wretched state for life.