Clinical profile of molluscum contagiosum in children versus adultsDepartment of Dermatology and STD, JIPMER, Pondicherry, India. firstname.lastname@example.org; email@example.com
Chandrashekar Laxmisha, Devinder M Thappa, and Telanseri J Jaisankar
Dermatology Online Journal 9 (5): 1
Molluscum contagiosum mainly affects children, but in adults the advent of HIV has modified its clinical spectrum. Our study is designed to ascertain the clinical profile of molluscum contagiosum in children and adults and to discover the effects of underlying HIV infection. During the study period of September 2000 to June 2002, 150 cases of molluscum contagiosum are screened and recruited at the Department of Dermatology and STD, JIPMER, Pondicherry. These include 137 children (85 male, 52 female) and 13 adults (10 male, 3 female). In children molluscum contagiosum is most commonly seen in the 5-10-year age group (58 cases), followed by the 1-5-year age group (53 cases), the 10-14-year age group (23 cases), and the younger-than-1-year age group (3 cases). In adults molluscum contagiosum is most commonly seen in the 14-20-year age group, followed by 2 cases each in the age groups 20-26 years, 26-34 years, and 34-40 years. The male-to-female sex ratio was 1.6:1 in children and 3.3:1 in adults. In both children and adults the most common sites affected are the head and neck, followed by trunk, upper extremity, genitalia, and lower extremity. It appears that the distribution of molluscum in our patients is significantly affected by the high proportion of HIV-positive adults in our sample. Seropositivity for HIV by ELISA is found in 1 of 137 children and 8 of 13 adults. In these HIV-positive patients, 2 cases of giant molluscum and one furuncle-like presentation are seen.
Molluscum contagiosum is caused by up to four closely-related types of pox virus, MCV-1 to MCV-4 and their variants [1, 2]. In small children, virtually all infections are caused by MCV-1; whereas in patients infected with HIV, MCV-2 causes the majority (60 %) of infections, suggesting that HIV infection-associated molluscum does not represent recrudescence of childhood molluscum . In all forms of infection, the individual lesions are relatively similar, smooth-surfaced, firm, dome-shaped, pearly papules averaging 3-5 mm in diameter. Some giant lesions may be up to 1.5 cm in diameter. A central umbilication is characteristic. The clinical pattern depends on the risk group affected.
Molluscum contagiosum occurs worldwide but is more prevalent in tropical areas . The infection is most common in children, sexually active adults, and persons with impaired cellular immunity, particularly HIV-positive patients. We have attempted to ascertain the clinical profile of molluscum contagiosum in children and adults, and to document whether HIV infection has changed the presentation.
During the study period September 2000 to June 2002, 150 cases of molluscum contagiosum are screened and recruited at the Department of Dermatology and STD, JIPMER, Pondicherry. For each patient, the demographic data, brief complaints, site of lesion, morphology, progression of the disease, family history, sexual history, and risk factors for HIV infection are noted. Relevant systemic examination is carried out. Diagnosis is established by clinical examination. Skin biopsy and Tzanck smear are done as needed to establish the diagnosis. ELISA for HIV testing is done if the patient has any underlying risk factors or if the lesions have bizarre and atypical morphology.
Cutaneous viral infections constitute 1.9 percent (404 cutaneous viral infection cases out of 20760 new cases) of the dermatology outpatient department cases. Molluscum contagiosum is the predominant viral skin infection, constituting 37.1 percent (150 cases) of cutaneous viral infections. These 150 cases of molluscum contagiosum (out of 404 consecutive cases with cutaneous viral infections in 20,760 new cases) are analyzed. These include 137 children (85 male, 52 female) and 13 adults (10 male, 3 female). In children, molluscum contagiosum is most commonly seen in the 5-10-year age group (58 cases), followed by the 1-5-year age group (53 cases), the 10-14-year age group (23 cases), and the younger-than-1-year age group (3 cases). In adults the most common age group is 14-20 years (7 cases), followed by 2 cases each in the age group of 20-26 years, 26-34 years and 34-40 years. The average age at presentation is 6.2 years in children and 21.8 years in adults with a range of 6 months to 36 years. The male-to-female sex ratio is 1.6:1 in children and 3.3:1 in adults.
Among the children, 65 cases are preschoolers (1-5 years old), 36 are students, 13 are laborers, 12 are house workers, 4 are vendors, and 4 are waiters. In adults the most common occupation is that of laborer (4 cases), followed by students (4 cases), drivers (3 cases), one waiter, and one commercial sex worker. A history of molluscum contagiosum in the family is present in 60 of 137 cases (40 %). The most common reasons for seeking care are cosmetic (117 cases), eye pain (17 cases), pain (9 cases), and itching (7 cases).
No obvious risk factors for HIV infection are found in 141 cases. HIV seropositivity is found in 9 cases. The mode of transmission of HIV is heterosexual in 7 cases (adults), bisexual in 1 case, and congenital in 1 child.
In children, single-site involvement is relatively more common (77 of 137 cases) than multiple-site involvement (60 of 137 cases). The most common sites affected are the head and neck, followed by trunk, upper extremity, genitalia, and lower extremity (Figs. 1 and 2). In adults, multiple-site involvement is more common (9 of 13 cases) than single-site involvement (4 of 13 cases), and the most common sites are the head and neck, followed by trunk, upper extremity, genitalia, and lower extremity (Table 1).
No. of cases (%)
No. of cases (%)
|Head and neck||91 (66.4%)||7(53.8%)|
|Figure 1||Figure 2|
|Typical molluscum contagiosum lesions over the genitalia and groin in a child (Fig. 1)|
|Molluscum lesions over the perineal region and thigh in a child (Fig. 2)|
In children, 72 patients have molluscum lesions smaller than 0.5 cm; 63 have lesions that are 0.5-1 cm; and 2 cases have molluscum lesions larger than 1 cm. The sizes of molluscum lesions in adults are 0.5-1 cm for 11 patients. Lesion sizes of less than 0.5 cm or greater than 1 cm are found in 1 patient each.
The number of lesions of molluscum contagiosum in children is 10-20 in 65 cases, followed by less than 10 in 50 cases, 20-30 in 15 cases, 30-40 in 5 cases, and more than 40 in 2 cases. In adults, 10-20 molluscum contagiosum lesions are seen in 6 cases, followed by less than 10 in 3 cases, 20-30 lesions in 2 cases, and more than 40 lesions in 2 cases.
The most common morphology is of a typical umbilicated papule, in 137 of 150 cases (92.6 %). Papules exclusively lacking umbilication are seen in 13 cases (8 %). A distinct configuration of lesions is also noted, including linear-Koebnerization (31 cases) (Fig. 3), annular (3 cases), arciform (2 cases), zosteriform (1 case) and grouped (3 cases). No special configuration is noted for 110 cases.
A few atypical presentations are also seen. These include one case of cutaneous horn, four of giant molluscum, and two of furuncle-like lesions (Table 2). Molluscum-associated dermatitis is observed in 15 of 150 (10 %) cases, 12 children and 3 adults. Molluscum contagiosum is seen in association with oral candidiasis (9 cases), viral warts (7 cases), conjunctivitis (5 cases), tuberculosis (3 cases), herpes zoster (2 cases), herpes genitalis (1 case), nephrotic syndrome (1 case), and diarrhea (one case).
No. of cases
No. of cases
|Koebner phenomenon in molluscum contagiosum over the thigh.|
Seropositive ELISA assays for HIV are found in 1 child (out of 137 children) and 8 adults (out of 13 adults, 6 males, and 2 females). In the adult HIV-seropositive patients, multiple-site involvement is more common (6 cases) than single-site involvement (2 cases). The most common sites of involvement are the head and neck (5 of 8 adult cases) (Fig.4). Giant molluscum lesions are present in 2 patients; one has a furuncle-like presentation (Fig.5). The associated disorders seen in adult HIV seropositive patients include oral candidiasis (8 cases), herpes zoster (2 cases), tuberculosis (3 cases), herpes genitalis (1 case), and genital warts (1 case).
|Figure 4||Figure 5|
|Numerous molluscum contagiosum lesions around the eye in an HIV-positive patient. (Fig. 4)|
|Furuncle like molluscum contagiosum over the forearm in an HIV-seropositive case. (Fig. 5)|
Molluscum contagiosum is a common cutaneous viral infection, but its incidence in most areas of the world is not reliably known . The disease is rare under the age of 1 year, perhaps because of transmission of maternal immunity and because of the long incubation period . Otherwise, the incidence seems to reflect exposure to others. In tropical countries, where children are lightly dressed, are in close contact with one another, and where personal hygiene may be poor, spread within households is not uncommon [4, 5]. The reported age of peak incidence is between 2-3 years in Fiji  and between 1-4 years in the Congo . In the West Sepik district of New Guinea, 93 percent of cases occur in children under age 10, with age range of 3 months to 57 years . The peak prevalence occurs at age 2. Other early epidemiological data support the notion that molluscum contagiosum is primarily a disorder of children, with a peak incidence at age 10-12 years [8, 9]. In an Indian children's hospital, of 315 cases of viral infection in children, 151 (47.93 %) cases are molluscum contagiosum. They include 80 males and 71 females. The age groups include 22 infants (14.56 %), 68 age 2-5 (45.03 %), and 71 age 6-12 (40.06 %) . Another study in India of the pediatric-age group reports that 4.6 percent of their patients are diagnosed with molluscum contagiosum . In our study, of 150 cases of molluscum, 137 are children (91.35 %), with a 1.6:1 male-to-female ratio. The most common age group is 1-10 years (111 cases). Out of a total of 404 cases of cutaneous viral infections, 150 (37.1 %) cases are found to be molluscum contagiosum, with a peak ages of 5-10 years (58 cases). Only 3 cases are seen in infancy. This is in contrast to the study by Sharma et al.  where 22 cases (14.56 %) are seen in infancy, with a peak in the preschool age period (45.03 %). Of our study group, 40 percent have a history of molluscum contagiosum in the family. This figure is similar to the study done in Alaska, where molluscum develops in 35 percent of exposed family members .
Although molluscum contagiosum is chiefly a disease of children, the incidence in adults is rising, probably as a result of sexual transmission.  The National Disease and Therapeutic Index survey found that the greatest number of cases occur among patients aged 20-29, although affected women are younger than affected men . Their analysis is limited to molluscum contagiosum diagnosed in patients 15 years or older. Our data show that only 8 percent (13 of 150 cases) of the total molluscum cases occur, in adults with a male-to-female ratio of 3.3: 1. A high proportion of these are HIV-positive. The average age among adults is 21.8 years. The results are similar to the study done in England and Wales where more than twice as many men as women are diagnosed .
Molluscum contagiosum is usually asymptomatic; a minority of patients complain of itching or tenderness . In our study, 117 cases (78 %) are asymptomatic; others complain of itching, ocular pain, burning sensation or other types of pain in the lesions. Ocular pain accompanies eyelid molluscum contagiosum. Curtin et al. found that molluscum can be the cause of unilateral chronic conjunctivitis when the eyelid is involved .
Children more typically develop multiple site lesions, most commonly on the face, trunk, and extremities, although perineal, scrotal, perianal, and groin lesions may be present as part of a wider distribution [9, 16]. Lesions are usually more widespread in children than in adults and, although adults with genital disease rarely develop extra genital lesions, 10-50 percent of infected children have lesions in the genital area . Similarly, in our study, the most common sites in children are the head and neck (91 cases), followed by the trunk (61 cases), and upper extremity (31 cases). Single-site involvement (56.2 %) is more common than multiple-site involvement (43.7 %) in the children we studied. The involvement of the genitalia in our study occurs in 20 cases (14.5 %) as a part of multiple site involvement. No history of sexual abuse of these children is obtained.
Previous reports on molluscum contagiosum in healthy adults describe a distribution of lesions involving the genital area, lower abdomen, and upper thigh [9, 18]. However, in adult patients with HIV infection, facial and multiple-site presentations are common, as in our patients. In our study, a minority of our patients are adults, but of these, 8 of 13 are HIV seropositive. The most common sites of involvement are the head and neck (5 of 8 cases). Widespread lesions of the face, and lesions persisting with a poor response to treatment, are highly characteristic of late HIV disease . Eyelid molluscum lesions may be the initial manifestation of AIDS . In our study, 1 child and 3 adults have extensive eyelid molluscum, one of which is complicated by a cutaneous horn.
Molluscum contagiosum lesions generally begin as tiny papules that grow over several weeks to a diameter of 3-5 mm, occasionally enlarging to 10-15 mm, producing giant molluscum . The number of lesions is usually fewer than 30 in immunocompetent hosts, but as many as several hundred may be seen . The size is less than 10 mm in 98.5 percent of children and 84.6 percent of adults in our study. In the children, 83.9 percent of the cases have fewer than 20 lesions; whereas, in the adults, 69.2 percent of the cases have fewer than 20 lesions. More than 40 lesions are seen in 2 cases each in adults and children, of which 3 are seropositive for HIV infection and 1 child has a primary immunodeficiency. Unusual lesions are more common in immunosuppressed patients. One of our HIV-seropositive cases has furuncle-like molluscum contagiosum. Three of the seropositive cases (2 adults and 1 child) have giant molluscum. Not only may molluscum contagiosum lesions become large in HIV-infected individuals, but also they may become markedly hyperkeratotic and atypical . Atypical lesions may resemble comedones, abscesses, furuncles, condylomas, syringomas, keratoacanthomas, basal cell carcinomas, ecthymas, sebaceous nevi of Jadassohn, and cutaneous horns . Importantly, disseminated fungal infections, specifically cryptococcosis, Penicillium marneffei infection and histoplasmosis, are reported to clinically mimic molluscum contagiosum and should be included in the differential diagnosis for these patients. Because of the atypical nature of mollusca in the HIV-infected patients, diagnosis is frequently dependent on biopsy.
The spectrum of molluscum has not recently changed in children. However, the advent of HIV infection has certainly modified the presentation and course in adults. Head and neck involvement or the presence of numerous and atypical lesions of molluscum contagiosum in an adult patient should prompt an investigation for the presence of HIV infection.
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