Leishmaniasis is a parasitic disease caused by
Leishmania, transmitted by the bite of some sandfly species and affects various age groups [
1]. Depending on the infecting
Leishmania species and host immunocompetence, there are cutaneous, mucocutaneous, and visceral forms of the disease [
1]. It is estimated that 350 million people are at risk of leishmaniasis [
2,
3]. The disease, in its various forms, affects at least 12 million people worldwide [
3-
5], with 1.5 to 2 million new cases per year [
2,
3].
Discussion
Symptomatic CL is diverse in its presentation and outcome [
1]. This clinical diversity is basically governed by the parasite, host factors, and immune-inflammatory responses [
1]. The incubation period of CL varies between several weeks to about a year [
5].
The eyelid is rarely involved in the cutaneous form of leishmaniasis, possibly due to movement of the lids preventing the fly vector from biting the skin in this region [
2-
5,
7]. Lid lesions may be caused by the bite, inoculation of the lid by the patient's fingers, lymphatic dissemination, the Koebner phenomenon (emergence of a new lesion after a mechanical trauma), or contiguous spread from a neighboring site [
4]. Lid CL may also occur in mucocutaneous leishmaniasis, due to
L. braziliensis, when infected material reaches the lid from nasal mucosal lesions via the nasolacrimal duct [
2,
5].
The typical CL lesion is a solitary ulcerating granuloma which starts as a small itching papule and then becomes scaled, crusted, and finally ulcerated [
5]. When the skin of the lids is affected, both upper and lower lids may be involved on either their outer or inner aspects [
5], most often on the lateral canthus [
4,
8]. The most common aspect of lid leishmaniasis is a chalazion-like lump but ulcerous, phagedenic, cancer-like forms [
8], and unilateral chronic granulomatous blepharitis may be observed [
9].
Approximately 2-5% of facial lesions are localized to the eyelids [
4,
5,
8]. In a study on 718 patients with CL, unusual variants were seen in 5.7% of the patients. Lid leishmaniasis, as an unusual presentation of CL, was seen in 4.9% of unusual cases in the study [
1]. Most atypical presentations, like paronychial, whitlow, lid, palmoplantar, and chancriform are probably related to the normal host response to the sandfly bite at these atypical sites [
1].
The pathologic pattern is comparative to what can be observed on the rest of the skin, but eyelid fragility results in a special risk for local spread [
4,
8].
Most atypical morphologies are correctly diagnosed, keeping a high index of suspicion regarding the endemicity of the disease in the region; but in a few cases, there is substantial delay. It is after therapeutic unresponsiveness and/or further investigations that an ultimate diagnosis of atypical CL can be made [
1]. Scraping from lesions, especially early in the infection, show leishman-Donovan bodies which are found mainly within histiocytes, but also can be found extracellularly. The presence of these bodies from a typical skin lesion was first described by Cunningham in 1885 [
5].
Clinical diagnosis of ocular leishmaniasis is very difficult [
4,
10], especially when appearing in non-endemic areas [
2]. Conjunctiva [
4,
7], cornea [
7], and sclera are rarely [
2] affected, while lachrymal ducts are sometimes [
8] affected [
4]. The disease, particularly its early papulonodular lesion [
2], may simulate other more common lesions such as chalazion, tumors (including basal cell carcinoma, especially its ulcerative form) [
2-
4,
10], dactiocystitis [
2,
4], tuberculosis (lupus vulgaris), syphilis [
5,
10], sarcoidosis [
10], keratoacanthoma (noular, tumor-like lesions, when ulcerated, in older individuals), histoplasmosis, and rhinoscleroma [
5]. Eczema was also added to the differential diagnosis list of lid leishmaniasis.
False diagnoses can be best avoided by taking a detailed and accurate history and identifying the pathogens as early as possible in smear cultures or by electron microscopy [
11].
When the outer aspect of the lid is involved, the disease is usually self-limiting and healing takes place by scarring for up to one year. A much more serious chain of events is to be expected when the inner aspect is involved [
5]. The contiguous spread from the skin of the lid will extend to involve the conjunctiva, sclera, and even cornea, with development of interstitial keratitis [
2-
4]. Secondary infection with destruction of underlying soft and bony tissue is common [
5]. Long-term complications of ocular leishmaniasis include lid deformity with all its consequences [
3,
4]. Stenosis of the lacrimal duct leads to a chronic discharging fistula and secondary conjunctivitis and uveitis [
5]. Therefore, ocular leishmanisis is considered a potentially blinding disorder; early diagnosis and rigorous treatment may prevent blinding complications [
2-
4]. Residual scarring and deformity may require surgical correction [
2]. The lid lesions in all our cases improved completely without any residual significant complication, because of early diagnosis and appropriate therapeutic approach.
Response to treatment in atypical cases is quite satisfactory [
1]. Treatment with pentavalent antimonial or sodium stibogluconate (pentostam) is typically curative and more effective. The dosage recommended by the World Health Organization is 20 mg/kg per day for 3 weeks [
2]. We underwent intralesional injection of meglumine antimoniate (glucantime) in all our patients. It appeared that this therapeutic regimen resulted in a good and relatively rapid response. Because of the loose tissue in the eyelid, injection is done easily, with the least feeling of pain and in large amount. We believe this is the cause of the satisfactory response.
Treatment failure may be due to both delay in diagnosis and incomplete therapy, as well as other factors such as resistant
Leishmania species or deficient host immune responses [
3].