159 Lichen planus
Salient features
History
• Medication history: thiazides, furosemide, beta-blockers, ACE inhibitors, phenothiazines, gold, organic mercurials, chloroquine, mepacrine, methyldopa, quinine, chlorpropamide, tolbutamide, proton pump inhibitors
• Occupational history: (whether the patient is in contact with colour film developer
• Hepatitis C infection: erosive-lichen planus is more common.
Examination
• Papular, purplish, flat-topped eruption with fine white streaks lace-like pattern (Wickham’s striae) (Fig. 159.1) over the anterior wrists and forearms, sacral region, ankles, legs and penis.
• Involvement of the skin is characterized by the ‘4Ps’: purple, polygonal, pruritic papules.
Fig. 159.1 Flat-topped, purple polygonal papules of lichen planus.
(With permission from Kliegman et al. 2007.)
• Look into the mouth (buccal mucosa, tongue, gum or lips) for a lace-like pattern of white lines and papules (Fig. 159.2). (Remember that oral lichen planus must be differentiated from leukoplakia.)
• Examine the scalp for cicatricial alopecia.
• Examine the nails for longitudinal ridging, pterygium formation from the cuticle (Fig. 159.3), 20-nail dystrophy dystrophy (roughened nail surface and brittle free nail edge) and total nail loss.
• Comment on eruptions that present along linear scratch marks (Koebner’s phenomenon).
• Comment on the residual hyperpigmented macules that lichen planus leaves in their wake.
Fig. 159.2 Lace-like keratoses, erythema and ulceration of the buccal mucosa.
(With permission from Goldman, Ausiello 2007.)
