Molluscum contagiosum (MC) is a double-stranded DNA virus of the Poxviridae family, which commonly infects human keratinocytes resulting in small, umbilicated, flesh-colored papules. The greatest incidence of MC is seen in the pediatric population and sexually active young adults, and it is considered a self-limited disease in immunocompetent individuals.1 With the emergence of the human immunodeficiency virus (HIV) and subsequent AIDS epidemic in the 1980s, a new population of immunocompromised individuals has been observed to be increasingly susceptible to MC with an atypical clinical presentation and a recalcitrant disease course.2 Although the increased prevalence of MC in the HIV population has been well-documented, it has been observed in other disease states or iatrogenically induced immunosuppression due to a deficiency in function or absolute number of T lymphocytes.
We present a case of a patient with long-standing psoriasis on biologic therapy who presented with MC with a subsequent workup that revealed AIDS. This case reiterates the importance of MC as a potential indicator of underlying immunosuppression. We review the literature to evaluate the occurrence of MC in immunosuppressed patients.
Case Report
A 33-year-old man initially presented for evaluation of severe plaque-type psoriasis associated with pain, erythema, and swelling of the joints of the hands of 10 years’ duration. He was started on methotrexate 5 mg weekly and topical corticosteroids but was unable to tolerate methotrexate due to headaches. He also had difficulty affording topical medications and adjunctive phototherapy. The patient was sporadically seen in follow-up with persistence of psoriatic plaques involving up to 60% body surface area (BSA) with the only treatment consisting of occasional topical steroids. Five years later, the patient was restarted on methotrexate 5 to 7.5 mg weekly, which resulted in moderate improvement. However, because of persistent elevation of liver enzymes, this treatment was stopped. Several months later he was evaluated for treatment with a biologic agent, and after a negative tuberculin skin test, he began treatment with etanercept 50 mg subcutaneous injection twice weekly, which provided notable improvement and allowed for reduction of dose frequency to once weekly.
At follow-up 1 year later, the patient had continued improvement of psoriasis with approximately 30% BSA on a treatment regimen of etanercept 50 mg weekly injection and topical corticosteroids. However, on physical examination, there were multiple small semitranslucent papules with telangiectases on the chest and upper back (Figure 1). Biopsy of a representative papule on the chest revealed MC (Figure 2). The patient was subsequently advised to stop etanercept and to return immediately to the clinic for HIV testing. He returned for follow-up 3 months later with pronounced worsening of disease and a new onset of blurred vision of the right eye. Cutaneous examination revealed numerous large erythematous plaques with superficial scale and cerebriform surface on the chest, back, abdomen, and upper and lower extremities involving 80% BSA (Figure 3). Biopsy of a plaque demonstrated psoriasiform dermatitis with neutrophils and parakeratosis consistent with psoriasis. Extensive blood work was notable for reactive HIV antibody and lymphopenia, CD4 lymphocyte count of 60 cells/mm3, and an HIV viral load of 247,000 copies/mL, meeting diagnostic criteria for AIDS. Additionally, ophthalmologic evaluation revealed toxoplasma retinitis. Upon initiation of highly active antiretroviral therapy (HAART) and continued use of topical corticosteroids, the patient experienced notable improvement of disease severity with approximately 20% BSA.
Figure 1. Molluscum contagiosum and psoriasis with multiple erythematous papules and plaques scattered on the chest.
Figure 2. Molluscum contagiosum histopathology revealed epidermal hyperplasia with hypergranulosis and central crater filled with molluscum bodies, with intracytoplasmic inclusions displacing keratohyalin granules and keratinocyte nuclei (H&E, original magnification ×100).
Figure 3. Psoriasis eruption of numerous confluent erythematous plaques with superficial scale and cerebriform surface on the back (A) and upper arm (B).