"Turkey ear" as a cutaneous maniestation of tuberculosis.

Lupus vulgaris is the most common morphological variant of cutaneous tuberculosis. Classical lupus lesions are often seen in the head and neck region. Turkey ear is a clinically descriptive term, previously being used for the earlobe with reddish indurated plaque lesions, which recently can be a sign for lupus vulgaris. A 65-year-old man presented with lupus vulgaris of the earlobe. The diagnosis was confirmed by conventional laboratory investigations and the patient showed well response to antituberculous therapy. This is the second reported case of "turkey ear" as a manifestation of cutaneous tuberculosis.

What was known?

“Turkey ear” is a descriptive term only used in lupus pernio of earlobe which can occur as one of the skin manifestations of sarcoidosis.

Introduction

The incidence of cutaneous tuberculosis has been increasing. Lupus vulgaris (LV) is the most common morphological variant of cutaneous tuberculosis. LV lesions are mostly reported on the head and neck region, rarely on earlobes. Although the diagnosis of LV can be established according to the clinical, histological and bacteriological criteria, the most confusing clinical appearance with lupus vulgaris of earlobe is lupus pernio.

Case Report

A 65-year-old man presented with an asympthomatic erythematous and swelling plaque lesion on his right ear, which had been gradually progressing for 15 years. On examination, red-brown infiltrated two plaques were palpated on the earlobe and just above [Figure 1]. The dorsum of the ear was particularly livid in color and atrophic cicatricial appearance was prominent [Figure 2]. ‘Apple-jelly’ nodules were seen on diascopy and also ‘fine-needle’ test was positive. There were no associated constitutional symptoms, history of previous trauma Bacille Calmette-Guérin (BCG) vaccination or medical history of systemic tuberculosis. There was no lymphadenopathy. The rest of systemic examination was within normal limits. All the hematological and biochemical investigations were normal. X-ray of the chest was normal. Purified protein derivative (PPD) showed an induration of 20 mm. Culture of the tissue for Mycobacterium tuberculosis revealed no growth. Skin biopsy from the plaque lesion on hematoxylin and eosin stain revealed an atrophic epidermis overlying caseating tuberculoid granulomas, consisting of lympho-histiocytes, epitheloid cells and Langhans giant cells in the papillary and upper reticular dermis [Figure 3]. No acid-fast bacilli were demonstrated on Ziehl-Neelsen staining but the polymerase chain reaction (PCR) was positive for mycobacterial DNA. The diagnosis of plaque form of LV was depending on clinical and histopathological findings and the patient was administered conventional antituberculous therapy of rifampin, isoniazid, pyrazinamide and ethambutol for 6 months. The lesion completely subsided with scarring and hyperpigmentation.

Figure 1

Red brown infiltrated plaques on the right earlobe and just above

Figure 2

Atrophic cicatricial appearance on the dorsum of the right ear

Figure 3

Lympho-histiocytes, epitheloid cells and Langhans giant cells in the papillary dermis (H and E stain, ×200)

Discussion

Cutaneous tuberculosis is a rare form of extrapulmonary tuberculosis.[1] The development of resistance to antitubercular drugs and the increase in diseases and conditions associated with immunodeficiency such as AIDS and chemotherapy have caused tuberculosis to increase recently. As a result, the incidence of cutaneous tuberculosis has been increasing as well.[2] LV is the most common morphological variant of cutaneous tuberculosis with an average prevalence of 0.37% among the general skin patients.[1] It is usually reinfection tuberculosis of the skin, which originates from tuberculosis focus in the body, spreading by hematogenous, lymphatic or contagious way. It rarely occurs after exogenous inoculation or BCG vaccination. However, in many cases the exact way in which LV develops is difficult to assess. It is more common in females than in males. All age groups are equally affected.[3] Classically well-demarcated soft reddish-brown papules or small plaques are often seen in the head and neck region. Deep-seated lesion displays a yellowish brown or “apple-jelly” coloration on diascopic examination.[1-7] Conventional morphological patterns of LV are papular, nodular, plaque, ulcerative, vegetating and tumid forms. Unusual variants are frambesiform, gangrenous, ulcerovegetating, lichen simplex chronicus, myxomatous and sporotrichoid types.[1] In the myxomatous form, huge soft tumors occur predominantly on the earlobes, which become grossly enlarged. Because of its rarity, the index of suspicion may be low.[4] In Europe, over 80% of lesions are on the head and neck, particularly around the nose.[58] LV lesions tend to be chronic, with new plaques appearing at the site of regressed atropic ones, and require appropriate therapy for complete healing.[2] Otherwise, they can persist for many years and even decades. The diagnosis of LV can be established according to a combination of clinical, histological and bacteriological criteria.[12] LV is seen in individuals with moderate immunity and a high degree of tuberculin sensitivity. In addition, its diagnosis remains bothersome, because detecting mycobacteria in skin lesions using conventional laboratory examination remains difficult and cultures are often negative.[5] Concomitant diagnosis by both culture and detection of mycobacterial DNA using PCR has been reported and may be useful where small numbers of mycobacteria are present.[4] Histopatologically, typical caseating necrotic granulomatous tubercule with Langhans giant cells, epitheloid cells and mononuclear infiltrate can be seen.

LV is treated by conventional antitubercular therapy consisting of rifampicin, isoniazid, pyrazinamide and ethambutol for 6 months.[467] If not properly treated, it presents a progressive chronic development whose long- term complications include cutaneous neoplasms.[9]

LV is often confused with various cutaneous disorders and some other granulomatous processes of the skin as lupus pernio, tuberculoid leprosy, lupoid leishmaniasis, deep-seated mycosis, cutaneous lymphoma and even granuloma annulare.[146-8] However, the most confusing diagnosis with lupus vulgaris of earlobe is lupus pernio. Lupus pernio is a relatively common skin manifestation of sarcoidosis characterized by slowly progressive bluish-red or violaceous indurated plaques and nodules that usually affect the nose, cheeks, ears, fingers, hands and toes. “Turkey ear” is a descriptive term previously used in lupus pernio of earlobe.[1] Williams et al. reported a case of lupus vulgaris, which had turkey ear appearance and suggested if turkey ear could be thought as a clinically descriptive term.[4]

In our case, localization and duration of the lesion were very typical for LV, in which the diagnosis was supported by tuberculin hypersensitivity and histopathological findings. Atrophic cicatricial changes at the dorsum of the ear were also significant for lupus vulgaris. The clinical appearance was very similar to turkey ear, which was previously described once as a sign of lupus vulgaris.[4] This is the second reported case of “turkey ear” as a manifestation of cutaneous tuberculosis. Thus, the term “turkey ear” is supposed to be used not only for sarcoidosis but also for lupus vulgaris.

What is new?

The clinical appearances of both lupus vulgaris and lupus pernio of earlobe are similar. Thus, the term “Turkey ear” may be also used for lupus vulgaris of earlobe.