Children are often brought medical attention for evaluation of various “lumps” or “bumps” on the skin. Infectious and neoplastic conditions that present with bumps such as molluscum contagiosum, folliculitis, and pyogenic granuloma, are discussed elsewhere. The lumps and bumps discussed in this chapter result from cyst formation (epidermal cysts and pilomatricomas) and benign tumors (Spitz nevus, mastocytomas, and juvenile xanthogranulomas). Linear and inflammatory conditions (lichen striatus, lichen nitidus, and frictional lichenoid dermatitis) are also discussed.

Many of these lesions are self-limited and only require symptomatic treatment. For example, typical juvenile xanthogranuloma are expected to involute over several years. Likewise, lichen striatus will also spontaneously resolve. However, pilomatricomas usually do not involute and may require surgical excision. Similarly, Spitz nevi that are clinically or histologically atypical require removal.

Distinguishing these lesions is necessary for prediction of the course of the eruption and for optimal management. This chapter will point out the key clinical features that can help establish the precise diagnosis and avoid unnecessary procedures or anxiety.