A healthy 3-year-old boy presented with multiple asymptomatic lesions on his face and hands of 1-year evolution, refractory to multiple treatments for viral warts. Physical examination revealed multiple skin-coloured to pink papules measuring less than 3–5mm located on the volar surface of both hands (Fig. 1).

Figure 1.

multiple skin-coloured and pink wart-like papules located on both palms.

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Acral Juvenile Xanthogranuloma Simulating Common Viral Warts.

The initial clinical impression established was common warts. However, dermoscopic assessment revealed a yellow structureless pattern with a peripheral hyperkeratotic rim (Fig. 2(a)) and some showed clouds of paler yellow deposits and linear vessels (Fig. 2(b)). Subsequently, a skin biopsy was performed demonstrating histiocytic intradermal infiltration, composed of xanthomatous cells and Touton type giant cells. In view of the clinical, dermoscopic and histopathologic findings a diagnosis of acral juvenile xanthogranuloma (JXG) was established.

Figure 2.

(a) Dermoscopic assessment of papules on the palms: Yellow structureless pattern and a peripheral hyperkeratotic rim. (b) *Clouds of paler yellow deposits, linear vessels and a peripheral hyperkeratotic rim.

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Juvenile xanthogranuloma (JXG) is a benign, self-healing, non-Langerhans cell histiocytosis that predominantly affects children.1 The clinical presentation is characterized by solitary or multiple, yellow papules and nodules.1,2 The most common sites involved are the head and trunk; however, JXG can develop in any part of the body, including mucosa and genitals.2 Diagnosis is based fundamentally on clinical observation in most cases, but may pose difficulties in atypical presentations or locations.2,3 Several dermoscopic features have been described on account of the evolutionary stages of JXG like the orange-yellow structureless pattern with erythematous border (setting sun sign), clouds of paler yellow globules, branched or linear vessels and whitish streaks.1

Differential diagnosis for acral JXG, specifically for solitary lesions, includes Spitz nevi, eccrine poroma,3,4 pyogenic granuloma,4 digital fibrokeratoma,4,5 amongst other lesions. Moreover, multiple acral JXG can easily be mistaken for common viral warts. However, dermoscopic analysis reveals lack of multiple punctate haemorrhages and papilliform surface, a characteristic feature of viral infection.6 In atypical cases, histopathologic analysis is required, showing accumulation of classic non-Langerhans cell histiocytes called Touton giant cells, positive for CD68 and negative for S-100 and CD1a.1

The present case highlights the great variability in clinical appearance of JXG and the fundamental role of dermoscopy, even for those clinically apparent benign dermatoses such as viral warts. Recognition of the characteristic dermoscopic features for acral JXG avoids unnecessary and painful treatments due to its benign clinical evolution.3,4