Cutaneous and eyes Aspergillus fumigatus infection

A spergillus fumigatus infection is a clinically rare condition. Here we report a case of facial cutaneous Aspergillus fumigatus infection where the skin lesions gradually extended to the eyes forming corneal and conjunctival ulcers that developed to panophthalmia. Fungus cultures were repeatedly performed on specimen from the eyes and from skin lesions. Aspergillus fumigatus was the pathogen identified morphologically and molecular biologically. CASE REPORT The patient is a 62-year-old female farmer with a history of diabetes for more than 20 years. She was pricked by a wood piece on her right face 8 years ago and a papule gradually occurred on the wound site. She did not pay attention to it at the beginning but the lesion became diabrosis and formed an ulcer half a year later and she has felt itching and pain since she developed this disease. Three years after the ulcer developed her right eye became involved with the formation of corneal and conjunctival ulcers that developed to panophthalmia. Four years later her left eye was also involved and she lost her sight completely (Figure 1). Wet mount examination found filamentous fungi in cornea secretions and in secretions under the ulcer crust. We performed bacterium and Mycobacterium tuberculosis cultures twice and no Mycobacterium tuberculosis was isolated. We did fungus cultures at five separate times and Aspergillus fumigatus was isolated from specimens taken from the skin ulcer secretion, cornea and tissue at the edge of the ulcer (Figure 2). We performed histopathologic examination of the edge of the ulcer tissue; however, hypha and spores were not found (Figure 3). As advised by authors of the published literature,1,2 we extracted DNA from samples of the Aspergillus fumigatus and type strain Aspergillus fumigatus A3 (from the edible fungus research institute of Yantai Ludong University). Polymerase chain reaction amplified Aspergillus fumigatus DNA with fungus universal primers ITS1: 5′-TCCGTAGGTGAACCTGCGG-3′ and ITS2: 5′-GCTGCGTTCTTCATCGATGC-3′ and generated a 300 bp fragment. The results of the PCR fingerprint coincide with the type strain Aspergillus fumigatus A3 (Figure 4). The sequenced sample DNA constant gene region (ITS1) was compared with the sequence of the gene BLAST (AF078889) and the alignment coincided with Aspergillus fumigatus to confirm the patient's infection with Aspergillus fumigatus. The patient was treated with intravenous amphotericin B, 50 mg per day for 1 month, then itraconazole was given, 0.4 g per day for 4 months, but no evident improvement was observed. The right eye was eventually removed by enucleation for intolerable pain.Figure 1. A:: Skin infection form superficial ulcer with clear margins. Facial skin lesion gradually expanded from skin to right eye. B: Right eye deformed, eyeball atrophied, conjunctival and corneal ulcer formed, indicating she developed panophthalmitis. C: Left eye was also involved. Manifests keratitis, corneal ulcer and cloudiness were the clinical features of mycotic keratitis. Although left eye lesion did not expand from skin, hand rubbing may inoculate pathogen to left eye directly.Figure 2. A:: Fungus colony on sabouraud dextrose agar culture (2 days), colony was white, flat, downy to powdery in texture. B: Seven days later, colony broadened, periphery of colony became light green. C: Sample smear of culture showed globular and setiform conidiospore, sporangiophore were short, hypha had no saeptums, superior part became enlarged and formed ampuliform vesicles (original magnification×400). D: Sporangiophore and hypha morphous under scanning electron microscope (original magnification×1000).Figure 3.: Skin lesion histopathologic examination showed the epidermis partially absent, hyperplasia, dermis basophilla degeneration, extensive lymphocyte, histiocyte and epithelioid cell infiltration (HE staining, A: original magnification×200, B: original magnification×400).Figure 4.: The result of ITS1 gene PCR amplification. Lane 1: Sample Aspergillus fumigatus PCR amplification product. Lane 2: Type strain-Aspergillus fumigatus PCR amplification product. Lane 3: 50 bp DNA ladder.DISCUSSION The Aspergillus species are ubiquitous molds that are most commonly found in the environment growing in decaying vegetation. Human beings are constantly exposed to this organism and frequently colonized by it.3 However, Aspergillus species is a major opportunist pathogen.4 Although invasive aspergillosis usually occurs in immune depressed individuals, such as those suffering from AIDS, receiving chemotherapy or transplant recipients, it may cause disease in healthy individuals and diabetes seems to be a predisposing condition.5 Cutaneous aspergillosis is a rare form of a locally invasive disease, it presumably enters through breaks in the skin, burns, surgical wounds, or intravenous catheter sites, mainly manifests necrotizing papules or ulcer.6,7 Aspergillus species are the most common cause of fungal keratitis. Trauma is the most common antecedent event in fungal keratitis, fungus then spread intraocularly and cause panophthalmitis.8 In the current patient, the primary infection site was facial skin and it gradually extended to the right eye. Hand rubbing may be a speculative etiological factor resulted in left eye involved, which may inoculate pathogen to eye directly. The diagnosis of Aspergillus infection is based on microbiologic and histopathologic examination. The secretion smear microscopy is a useful tool for screening of aspergillosis.8 Because Aspergillus fumigatus is widely found in nature, it is also a common laboratory contaminant, so repeated culture is a rigorous criterion for diagnosis.9 Cutaneous aspergillosis histological examination mainly manifests epithelioplasia, inflammatory reaction within the superficial and deep dermis. Finding hypha and spores in histopathological examination is not essential for aspergillosis diagnosis. According to Rickerts and coworkers’ report, only 48% of mold hypha and spores could be detected histopathologically in tissue specimens.10 It is important for physicians to recognize that Aspergillus fumigatus can cause severe soft tissue infection. Aspergillus keratitis is a blinding infection of the cornea, which can lead to the loss of the infected eye if not controlled properly. Early diagnosis and rapid initiation of systemic effective antifungal agent therapy is critical for successful outcome.