Solitary Cutaneous Mastocytoma on an Infant’s Face

Authors:
Kelley Ward, MD
Resident Physician, Department of Pediatrics, University of Florida, Gainesville, Florida

Ruchita Kachru, MD
Assistant Professor, Department of Pediatrics, University of Florida, Gainesville, Florida

Sanjeev Tuli, MD
Professor, Department of Pediatrics, University of Florida, Gainesville, Florida

Citation:
Ward K, Kachru R, Tuli S. Solitary cutaneous mastocytoma on an infant’s face [published online August 2, 2019]. Consultant360.

The parents of a 2-month-old boy brought him to the clinic with concern for what they described as “bug bites” on his face. The infant had red blanching papules lateral to his left eye (Figure 1). The lesion had an orange-peel appearance. He was sent home with observation with a suspected diagnosis of insect bite.

Figure 1. An infant’s red blanching papules lateral to his left eye, initially suspected to be insect bites.

The infant returned a week later for a well-child check. The parents reported that one red spot had been present on the child’s face for 3 weeks without resolution. They noticed that throughout the day, the lesion sometimes changed in intensity and looked more prominent than at other times. The day before, they had noted a small amount of clear drainage from the lesion. He had been feeding well and was afebrile and without any other lesions or systemic signs of illness. The parents had not applied any creams or tried any other interventions. He was an otherwise healthy, full-term infant who was growing and developing as expected.

On physical examination, a red, blanching, 1-cm papule with evidence of a ruptured bulla was present lateral to the left eye (Figure 2). When the lesion was lightly stroked, it became redder and more prominent (Darier sign).

Figure 2. One week after initial presentation, a red, blanching, 1-cm papule with evidence of a ruptured bulla was present lateral to the left eye.

The lesion was not vesicular, making infectious causes such as herpes simplex less likely. If it were a simple insect bite, resolution would have been expected by 3 weeks. The differential diagnosis also included bullous impetigo and juvenile xanthogranuloma. Given the pathognomonic Darier sign, the infant received a clinical diagnosis of solitary mastocytoma.

Discussion. Solitary mastocytoma is 1 of 3 types of cutaneous mastocytosis. Cutaneous mastocytosis is a range of disorders unified by the presence of dense collections of mast cells within the dermis. The other 2 types of cutaneous mastocytosis are urticaria pigmentosa and diffuse cutaneous mastocytosis.¹

Cutaneous mastocytoses may present at birth. A peak incidence is during infancy with another peak in young adults. Lesions that develop during infancy tend to regress, whereas adult-onset lesions tend to persist. Solitary mastocytoma commonly arises in early infancy or may be present at birth. Physical examination findings are noteworthy for a peau d’orange (orange peel) texture; the color of the lesion can be pink, yellow, or tan, and it may be rubbery. Wheals or bullae are common manifestations. The size can range from 1 to 5 cm. Systemic signs are rare.¹ If the diagnosis is unclear based on physical examination findings, a skin biopsy or a serum mast-cell tryptase level can be obtained.²

Treatment options include topical corticosteroids or antihistamines.³ In general, treatment is not required for solitary mastocytoma, since there are generally no systemic symptoms. Most lesions (90%) resolve by age 7 years.²

Since this infant had a single solitary lesion without systemic symptoms, the benign clinical course was explained to the parents, and observation alone was chosen for this patient. At his 6-month well visit, the lesion had nearly resolved aside a small 1-mm residual papule (Figure 3).

Figure 3. At the child’s 6-month well visit, the lesion had nearly resolved aside a small 1-mm residual papule.

At further well-child visits, the patient will be monitored closely for complete resolution of the lesion as well as development of systemic signs or further lesions.

References:

1. Galbraith SS. Diseases of the dermis. In: Kliegman RM, Stanton BF, St Geme JW III, Schor NF, eds. Nelson Textbook of Pediatrics. Vol 2. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 659.
2. Ben-Amitai D, Metzker A, Cohen HA. Pediatric cutaneous mastocytosis: a review of 180 patients. Isr Med Assoc J. 2005;7(5):320-32
3. Kiszewski AE, Durán-Mckinster C, Orozco-Covarrubias L, Gutiérrez-Castrellón P, Ruiz-Maldonado R. Cutaneous mastocytosis in children: a clinical analysis of 71 cases. J Eur Acad Dermatol Venereol. 2004;18(3):285-290.