Scrub typhus is a common disease caused by Orientia tsutsugamushi in the tropical/ temperate zone. It usually shows the skin lesions, including eschar, but erythema multiforme is rare.

Scrub typhus is a disease caused by a rickettsia, Orientia tsutsugamushi, and patients usually show a specific eschar, papules, and erythema ranging in size from rice grains to beans, with treatment being antibiotics for mild cases [1, 2].

However, severe cases can occur. A 72-year-old man who was taking oral amoxicillin 500 mg three times/day following tooth extraction 10 days earlier presented with general malaise and erythema multiforme with target lesion, and a drug eruption was diagnosed (Figure 1A). No medications were given, and antibiotic treatment was withdrawn, but he lost consciousness half a day later and was transported to the Emergency Department.

The characteristic eschar from a tick bite was found (Figure 1B), and scrub typhus, such as tsutsugamushi disease, was diagnosed. We found anti-Tsutsugamushi IgG and IgM were also increased significantly. Intravenous minocycline 100 mg twice/day was started immediately, and his fever decreased the day after admission and finally improved two weeks later.

Erythema multiforme is a very rare skin lesion in tsutsugamushi disease and is often misdiagnosed as a drug eruption [3, 4], but severe rickettsial diseases should be considered, and efforts should be made to identify the characteristic eschar caused by the tick bite.

Conflict of Interest: The author has no competing interests to disclose.

Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Figure 1

The patient’s skin lesions. (A) Erythema multiforme is found on the whole of his back. (B) The characteristic eschar is found on the medial side of his left thigh.