Cringeworthy

These lesions had been present for three weeks on the posterior and right lateral surfaces of the neck of a 19-year-old beach lifeguard from southern California.  They are serpiginous in shape, raised and erythematous, but he was asymptomatic.

The case was published in the New England Journal of Medicine, which will be behind a paywall for almost all readers here, so I'll offer some excerpts from a discussion of the case at Ars Technica:

The best clue to the cause—besides the look of the rash—was that the teen told doctors he worked as a beach lifeguard and liked to lie in the sand.

Despite the lack of itchiness and the higher location of the rash, the doctors concluded it was likely cutaneous larva migrans (CLM) from a hookworm, which he got from lying on a poopy beach. The standard treatment for CLM is ivermectin, an antiparasitic drug that still doesn't work against COVID-19 (despite what the new US health secretary has falsely claimed), but has proven useful against hookworms. After a two-day course of ivermectin, the teen's rash cleared up.

These "extraintestinal" hookworms (as they're called in humans) pop up in the US from time to time. For instance, in July 2006, health officials in Miami-Dade, Florida, discovered an outbreak of CLM at a summer camp, where 18 campers and four staff were ultimately found to be infected. The likely source, investigators concluded: a playground sandbox that some feral cats used as a litter box.

In most cases, the rash from a wandering worm is in a foot, ankle, thigh, or rear—basically from a person walking or sitting in fecal-contaminated soil with exposed skin.

More info about hookworms at the link.