A Typical but Rare Case of Solitary Tinea Auricularis

Introduction

Tinea auricularis refers to the uncommon and neglected dermatophytosis. Most of the tinea auricularis cases have tinea capitis or tinea faciei involving the ears,¹ with the clinical manifestations of imitated eczematous erythema.² Solitary tinea auricularis is rarely seen in clinic. Here, a case of typical tinea auricularis that might be related to previous infection and antimicrobial treatment was reported.

Case Presentation

An otherwise healthy, 35-year-old woman presented to the dermatology clinic with a 2-week history of rash on her right ear. She was previously diagnosed with eczema and topical use of desonide cream failed. On physical examination, there was annular erythema with scaly borders centered around the external acoustic pore (Figure 1), with no retro-auricular, scalp or face involvement. Skin scrapings were collected from the patient. Direct microscopic examination was positive (Figure 2), and all fungal cultures grew colonies of Trichophyton rubrum (GenBank accession number: OP856520 [isolated from the patient, 629bp]). The patient was diagnosed with tinea auricularis.

Figure 1 Annular erythema on the right ear.

Figure 2 Numerous septate hypha could be detected under calcofluor white staining (magnification ×400).

After inquiry, the patient reported experiencing suppurative otitis media one month ago, which was treated with levofloxacin combined with dexamethasone under endoscopic irrigation. Local infection or external drug application may change the local skin immune situation and microbiota, which then becomes one of the causes of fungal infection. Treatment with topical clotrimazole cream was initiated and after 3 weeks of therapy the skin lesions had resolved. The patient was contacted 3 months after the completion of therapy, and she confirmed that there had been no recurrence of the rash.

Discussion

Superficial fungal infection of auricle is rarely reported, and there is no typical annular erythema in the reported cases of tinea auricularis at present, with itching and accumulation of cerumen being the most commin symptoms. One study performed microscopic examination of fungi on patients with skin symptoms in the ear, and discovered positive results in 19 (35%) out of 54 patients, over the age of 44 years.² It reminds us that for old patients with skin symptoms in the ear, microscopic examination of fungi should be actively performed to exclude the possibility of infection. Thus, tinea auricularis was rarely occurs in young adults.

According to a recent study, tinea auricularis mostly coexists with tinea faciei or capitis.¹ It has been found that most children with tinea capitis also have ear involvement, which is also called the “ear sign”.³ Solitary tinea auricularis is uncommon. Zhi et al reported a case of child with unidentifiable ear auricularis, which manifested as persistent erythematous papules and pruritus in the left ear.⁴ Hamzelou et al reported an 80-year-old man with fungal infection on the ear who presented with the clinical manifestations of erythema, scales and pustules. Tinea auricularis is uncommon and easily misdiagnosed; however, the notable observation is the sole involvement of the ear.

Conclusion

In conclusion, we reported a case of annular erythema with scales around the ear canal orifice. For young and middle-aged patients with ear skin symptoms, previous histories of infection and treatment should be taken into consideration. Typically, microscopic examination of fungi is recommended for those with related history of infection and treatment.