<unk>  is usually associated with a well-defined connective tissue disease, lupus erythematosus or rheumatoid arthritis most commonly, and often presents with eroded or ulcerated symmetrically distributed umbilicated papules or nodules on the elbows.
Palisaded neutrophilic and granulomatous dermatitis
Perifollicular mucinosis
Subepidermal calcified nodule
Self-healing papular mucinosis
Relapsing linear acantholytic dermatosis
Vacuolar interface dermatitis
Central giant-cell granuloma
Self-healing juvenile cutaneous mucinosis