Peer Reviewed


Infantile Perianal Protrusion in a 10-Month-Old Boy

Alexander K. C. Leung, MD1,2 • Kin Fon Leong, MD3 • Joseph M. Lam, MD4 • Andrew A. H. Leung, BSc5

1Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
2Alberta Children’s Hospital, Calgary, Alberta, Canada
3Pediatric Institute, Kuala Lumpur General Hospital, Kuala Lumpur, Malaysia
4Department of Pediatrics and Department of Dermatology and Skin Sciences, University of British Columbia, Vancouver, British Columbia, Canada
5Faculty of Medicine, St. George’s University, Grenada

Leung AKC, Leong KF, Lam JM, Leung AAH. Infantile perianal protrusion in a 10-month-old boy. Consultant. 2021;61(5):e26-e28. doi:10.25270/con.2020.09.00005

The authors report no relevant financial relationships.

Alexander K. C. Leung, MD, #200, 233 16th Ave NW, Calgary, AB T2M 0H5, Canada (


A 10-month-old boy was noted to have an asymptomatic protrusion in the perianal area during a routine physical examination. He had bowel movements every other day, and the stools had been hard since the introduction of solid food at 6 months of age.

Physical examination revealed a pyramidal protrusion in the perianal area in the 6-o’clock position (Figure 1). The protrusion was flesh-colored, smooth in surface, and firm in consistency. There was no anal fissure or lichen sclerosis et atrophicus noted.

Fig 1
Figure 1. A pyramidal protrusion in the perianal area in a 10-month-old boy.

Based on the characteristic appearance of the lesion, a clinical diagnosis of infantile perianal protrusion was made. The patient was treated with an increased intake of high-fiber food, liberal intake of fluid, and lactulose, which led to relief of the constipation in 2 weeks’ time. The parents were advised to gently wipe and clean the perianal area of the child after defecation. The mass subsided in 6 months.


Characteristically, infantile perianal protrusion, also known as infantile perianal pyramidal protrusion or infantile perineal protrusion, presents as an asymptomatic, smooth-surfaced, rose red or flesh-colored, soft-tissue protrusion.1-3 The protrusion is usually solitary and located anterior to the anus in the midline with the major axis parallel to the median raphe.1-3 Concomitant anterior and posterior protrusions have rarely been reported.2 The protrusion is usually pyramidal in shape, except in the rare congenital case where the protrusion assumes a leaf-like appearance.1,2 The condition is often constitutional or idiopathic but may occur in association with constipation, mechanical irritation from vigorous wiping of the perineal area, or anogenital lichen sclerosis et atrophicus.1,4 There is a female predominance, presumably due to an inherent weakness in the perineal region in girls.1 The condition tends to resolve with time, usually within several months, especially if the underlying cause is properly treated.1

The differential diagnosis includes condylomata acuminata, hemorrhoids, rectal prolapse, and molluscum contagiosum. The characteristic features of these conditions are summarized in the Table. Condylomata acuminata are anogenital warts caused mainly by human papillomaviruses 6 and 11. The lesions usually begin as flesh-colored, soft, flat or ragged papules (Figure 2), which may with time coalesce to form velvety plaques, discrete warty papules, or cauliflower-like growths.5 Condylomata acuminata occur most commonly in the perineal areas. The lesions are usually asymptomatic and multiple. The condition is most common among sexually active individuals aged 16 to 35 years.5 Condylomata acuminata in children younger than 3 years of age are often due to vertical transmission of the virus during birth. Occurrence in prepubertal children older than 3 years should raise questions of child abuse. If left untreated, condylomata acuminata may resolve spontaneously, stay the same, or increase in size and number.5


Fig 2
Figure 2. Condylomata acuminata lesions usually begin as flesh-colored, soft, flat, or ragged papules.

Typically, a hemorrhoid presents with an anal mass/protrusion (Figure 3), painless rectal bleeding, or the feeling of incomplete evacuation. The mass/protrusion usually returns to the rectum spontaneously but may need to be manually reduced. The condition usually occurs in individuals over 50 years of age, especially in those with constipation and, at times, carcinoma of the colon. Without proper treatment, a hemorrhoid tends to persist.

Fig 3
Figure 3. A hemorrhoid typically presents with an anal mass/protrusion.

Characteristically, a rectal prolapse presents with a bright or dark red mass, with or without blood and mucus, protruding from the anus, and exacerbated during straining or defecation. The mass may reduce spontaneously or may require manual reduction. Generally, a rectal prolapse is painless but may be associated with mild discomfort. The condition usually occurs in elderly individuals. When rectal prolapse occurs in children, there is almost always an underlying cause such as postsurgical correction of anorectal malformation, malnutrition, increased intra-abdominal pressure, cystic fibrosis, constipation, and pelvic floor weakness. The condition tends to persist unless the underlying cause is treated.

Typically, molluscum contagiosum presents as asymptomatic, discrete, firm, smooth, dome-shaped, pearly white or fleshed-colored, waxy papules with characteristic central umbilication (Figure 4).6 Central umbilication can be hard to observe in small lesions and young children. Lesions are most common in moist regions and in areas of skin rubbing. Molluscum contagiosum is most commonly seen in preschool and elementary school children. Most lesions resolve spontaneously in 6 to 18 months.6,7 A giant lesion in the anal area may mimic an infantile perianal protrusion.

Fig 4

Figure 4. Molluscum contagiosum typically presents as asymptomatic, discrete, firm, smooth, dome-shaped, pearly white or fleshed-colored, waxy papules with characteristic central umbilication.


  1. Leung AKC, Leung AAM, Hon KLE. Infantile perianal protrusion. Consultant. Published August 18, 2017. Accessed September 1, 2020.
  2. Leung AKC. Concomitant anterior and posterior infantile perianal protrusions. J Natl Med Assoc. 2010;102(2):135-136. doi:10.1016/s0027-9684(15)30514-9
  3. Güngör Ş, Güngör S. Infantile perianal (perineal) pyramidal protrusion. Indian Dermatol Online J. 2014;5(suppl 2):S142-S143. doi:10.4103/2229-5178.146203
  4. Patrizi A, Raone B, Neri I, D’Antuono A. Infantile perianal protrusion: 13 new cases. Pediatr Dermatol. 2002;19(1):15-18. doi:10.1046/j.1525-1470.2002.00010.x
  5. Leung AKC, Barankin B, Leong KF, Hon KL. Penile warts: an update on their evaluation and management. Drugs Context. 2018;7:212563. doi:10.7573/dic.212563
  6. Leung AKC, Barankin B, Hon KLE. Molluscum contagiosum: an update. Recent Pat Inflamm Allergy Drug Discov. 2017;11(1):22-31. doi:10.2174/1872213X11666170518114456
  7. Leung AKC. The natural history of molluscum contagiosum in children. Lancet Infect Dis. 2015;15(2):136-137. doi:10.1016/S1473-3099(14)71061-8