Hyalohyphomycosis (Fusariosis): Atypical Presentation in an Immunocompetent Individual Responding to Itraconazole

Abstract

Hyalohyphomycosis includes infections caused by various fungal species that produce hyaline, septate, branched hyphae. Fusarium is one such species which usually causes multiple papulo-nodules, ecthyma gangrenosum-like ulcers in immunocompromised individuals. Also, fusariosis is usually difficult to manage and responds favorably to amphotericin B, voriconazole, and posaconazole in disseminated cases. Here, we report an atypical case of cutaneous fusariosis in an immunocompetent individual who presented with multiple large cystic swellings, psoriasiform plaques, and palmoplantar keratoderma, and the patient responded completely to itraconazole.

Introduction

The term “Hyalohyphomycosis” includes group of rare fungal infections caused by colorless (hyaline), septate, branched, or unbranched molds of various species. Fusarium is one such opportunistic fungus species which usually causes invasive or disseminated infection in immunocompromised individuals and superficial infections in immunocompetent individuals.[1] Cutaneous fusariosis generally presents as multiple painful, erythematous papules, or nodules with or without central necrosis, onychomycosis, and periungual cellulitis.[2] We present an atypical case of fusariosis, in the form of multiple large cystic swellings, psoriasiform plaques, and palmoplantar keratoderma which showed complete resolution with itraconazole.

Case Report

A 20-year-old female presented with multiple asymptomatic soft swellings over the face and trunk, predominantly over back of 2 years duration. They initially started as small swellings of about 1 cm which gradually progressed to reach the present size. Patient had no history suggestive of immunosuppressive state (prolonged steroid therapy, chemotherapy, hematological malignancy, organ transplantation). Patient was afebrile and well built. Systemic examination was normal. Cutaneous examination revealed multiple non-tender, skin-colored cystic swellings over face and trunk of variable sizes with the largest being around 14 × 12 cm on the upper back [Figure 1] which on piercing yielded yellowish white pultaceous material. Also, the patient had well defined, thin, scaly, slightly erythematous, psoriasiform plaques over bilateral upper and lower limbs [Figure 2a], focal palmoplantar keratoderma [Figure 2b], onychomycosis with nail dystrophy.

Figure 1.

Large cyst of about 14 × 12 cm over upper back

Figure 2.

(a) Well-defined, thin, mildly scaly, plaques on forearm (b) Focal plantar keratoderma

Preliminary workup for immunosuppression like HIV serology, tuberculosis was negative, candida prick test was reactive, total leucocyte count and CD4:CD8 ratio were normal. Potassium hydroxide (KOH) mount of the pultaceous material from large and small cysts and skin scrapings showed large non-pigmented, hyaline septate hyphae with both fusoid macroconidia and microconidia characteristic of the genus Fusarium. Skin biopsy and excision biopsy of largest cyst showed hyperkeratosis with multiple hyaline septate hyphae in the epidermis and dermis with lymphocytic infiltrate in the dermis [Figure 3a]. Masson–Fontana stain did not reveal any pigment. Gomori methanamine silver and Periodic acid Schiff stain [Figure 3b] showed septate hyaline hyphae. Culture of the material and affected nail clipping culture on Sabourad dextrose agar grew fungal colonies of the Fusarium genus. Large cyst was excised, and patient was started on oral itraconazole (200 mg/day) and was regular followed-up [Figure 4a]. Scaly plaques and keratoderma showed very slow but complete resolution after 6months of therapy [Figure 4b]. Smaller cysts did not resolve completely but showed regression in size.

Figure 3.

(a) Colonies of branching septate hyphae and foreign body giant cells (H and E ×100) (b) Acute angle branching, septate hyphae (PAS stain, ×100)

Figure 4.

(a) Post-cyst excision with decrease in size of smaller cysts after 2 months of itraconazole (b) Resolution of scaly plaque on forearm after 5 months of itraconazole

Discussion

Hyalohyphomycosis includes opportunistic fungal infections caused by molds including species of Fusarium, Acremonium, Pseudallescheria, Paecilomyces, Penicillium, and Scedosporium all of which produce hyaline, septate, branched, or unbranched mycelia.[1]

Fusarium is an opportunistic fungal pathogen causing invasive or disseminated infection in immunocompromised individuals. Neutropenia and hematological malignancies are the two most important risk factors for the development of fusariosis.[3] A study conducted by Nucci et al.[4] on cutaneous fusariosis showed preceding skin breakdown, localized involvement, slow pace of progression, and good response to therapy in immunocompetent individuals. In contrast, skin involvement in immunocompromised patients was only occasionally preceded by skin breakdown and typically manifests in four major clinical presentations: fever and disseminated skin lesions, pneumonia, fever and positive blood culture for a mold, and superficial infection in the feet with subsequent lymphangitis.[5]

Three forms of skin lesions have been reported so far in literature: multiple subcutaneous nodules, ecthyma gangrenosum-like lesions, and target lesions consisting of ecthyma form lesions surrounded by a thin erythematous rim,[6] with a predilection for the extremities. Fusariosis can also lead to onychomycosis and nail dystrophy in immunocompetent individuals[6] as seen in our patient. However, our patient presented with large cystic lesions, psoriasiform plaques, and palmoplantar keratoderma. Flattening of nodular lesions, reduction in size, and lack of new lesions suggest good response to treatment. However, continuous appearance of new skin lesions in a patient under treatment is a clear sign of therapeutic failure.[7]

Fusarium infection is considered to be local if there is histopathological evidence of invasion with positive culture but without systemic involvement. It is labelled as disseminated infection if there are two positive cultures from either internal organs or blood culture or both. Microscopically, Fusarium spp. appears as hyaline, septate, non-pigmented hyphae of about 3-8μm in diameter, typically branching at acute or right angles similar to Aspergillus spp. but, the presence of both fusoid macroconidia and microconidia is characteristic of the genus Fusarium.[8] Fusariosis is difficult to treat and is shown to have favorable outcome with voriconazole, p-osaconazole, and amphotericin B. In contrast, our patient showed almost complete resolution to itraconazole.[9]

We thus present an atypical case of cutaneous fusariosis in an immunocompetent individual with two distinguishing features—rare clinical presentation of cystic swellings, psoriasiform plaques, palmoplantar keratoderma, and good therapeutic response to itraconazole. However, molecular identification of Fusarium was not done in our patient which is the limitation of this report.

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The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.