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Dermatology Diagnosis

When A Postoperative Patient Presents With Purple Papules Surrounding A Surgical Incision

A 30-year-old man returned to clinic 10 weeks following primary repair of an Achilles tendon rupture on his left extremity.  

The patient noted discolored skin lesions around his surgical site that had been present for the past two weeks. He reported mild pruritus in association with these skin lesions. He had no instigating factors other than his recent surgery and cast boot use.

The physical exam showed a well-healed surgical scar to the posterior left heel and ankle with flat-topped purple papules and plaques. Scattered around this area and ankle were several flat-topped purple polygonal papules, some with Wickham striae. The lesions had a characteristic clinical appearance of lichen planus but given the lesions’ association with the surgical site, the patient received a referral to dermatology for further evaluation. A skin biopsy performed by dermatology confirmed the diagnosis with histopathologic findings characteristic of lichen planus.

Physicians suspected that injury to the skin from recent surgery contributed to the dermatologic condition in this patient. Given the localized area and only mild pruritus, the patient used topical steroids (fluocinonide 0.05% ointment two times per day). The patient’s skin lesions resolved after six months with no sequela.

Key Questions To Consider

1. What is the diagnosis of these lesions?
2. What pathologies are in the differential diagnosis of these lesions?
3. What is the preferred treatment course for these lesions?
4. How can you advise your patient on the course and outcome of this perceived surgical complication?

Answering The Key Diagnostic Questions
1. The diagnosis is lichen planus with the Koebner phenomenon of skin lesions developing in the area of local skin trauma secondary to recent surgery.
2. Differential diagnoses for these skin lesions include allergic contact dermatitis, psoriasis, lichen simplex chronicus, pityriasis rosea, tinea and verrucae.
3. The preferred treatment for these lesions is topical corticosteroids.
4. Advise the patient that the lesions are self-limited and will typically resolve within six to 12 months.

What You Should Know About Lichen Planus And The Koebner Phenomenon

The diagnosis is lichen planus (Koebner phenomenon). Lichen planus is a T cell-mediated autoimmune disorder that produces characteristic red and purple plaque-like skin lesions. Lichen planus causes cutaneous eruptions but can also affect the nails and mucous membranes. There are several clinical variations of lichen planus including: hypertrophic, atrophic, erosive, ulcerative, follicular, annular, linear, vesicular, bullous, actinic, pigmented and pemphigoid.1

The etiology of lichen planus is unknown but researchers have found the condition to be associated with disorders that affect the immune system as well as hepatitis C virus infection.2,3 Contributing factors to lichen planus include: genetic predisposition, physical and emotional stress, injury to the skin, localized skin disease like herpes zoster, systemic viral infection, contact allergy and certain medications.4 The Koebner phenomenon or isomorphic response is the development of skin lesions in areas of skin trauma. The Koebner phenomenon is common in lichen planus.

The characteristic features of lichen planus are commonly described with the six Ps: pruritic, polygonal, planar, purple, papules and plaques.5 These lesions range in size from 1 to 10 mm. Wickham striae, fine white striations, are frequently visible on the surface of these lesions. Cutaneous lesions are frequently present on the front of wrists, lower back and ankles. Resolving lesions can leave gray-brown macules that can take more than a year to resolve.

Making An Accurate Diagnosis Of Lichen Planus

There are numerous clinical variants of lichen planus that can make diagnosis difficult.1 Hypertophic lichen planus most commonly occurs on the shins and interphalangeal joints. This frequently is the most pruritic variation of lichen planus. Atrophic lichen planus is rare. It is characterized by a few white-blue papules and plaques with an atrophic center. Annular lichen planus consists of circular groups of papules with unaffected central skin. Linear lichen planus consists of papules in a line. Linear lichen planus may result from skin trauma (Koebner phenomenon).

Bullous or pemphigoid lichen planus is characterized by the development of bulla and vesicles within the skin lesions. Similarly, ulcerative lichen planus is characterized by painful bullae and ulceration of the skin lesions. Ulcerative lichen planus most commonly occurs on the feet but this is a rare variation. Pigmented lichen planus is characterized by hyperpigmentation of flexor surfaces and sun-exposed areas.
Physicians often diagnose lichen planus based on the classical clinical appearance and frequently confirm the diagnosis with a punch biopsy of a representative lesion. Histopathologic evaluation of these lesions shows characteristic findings of an infiltrating lichenoid band of lymphocytes at the epidermal-dermal junction with damage to the basal cell layer and saw-tooth irregular psoriasiform hyperplasia of the epidermis.6

The differential diagnosis for lichen planus includes allergic contact dermatitis, psoriasis, lichen simplex chronicus, pityriasis rosea, tinea and verrucae.7 Lichen planus on the lower extremity frequently has an atypical clinical appearance necessitating biopsy for confirmatory diagnosis.

Relevant Insights On Treatment And Prognosis

High-potency topical corticosteroid ointment is the first-line treatment for cutaneous lichen planus.7-9 One can manage itching that does not resolve with topical steroids with antihistamines including oral diphenhydramine or hydroxyzine. Researchers recommend oral corticosteroids for severe, widespread cases of lichen planus.8,9

Phototherapy is an alternative treatment for severe cases of lichen planus.10 Studies have shown intra-lesional steroid injections (0.5 to 1.0 mL triamcinolone acetonide per 2 cm lesion) to be an effective treatment for hypertrophic forms of lichen planus.8 Research has additionally shown the effectiveness of acretin, an oral retinoid, in the treatment of lichen planus, but use of this medication is limited by both cost and teratogenic effects.7,11

Lichen planus is a self-limited disease that typically resolves within six to 12 months. Recurrence of lichen planus is common. Complications resulting from lichen planus are rare. Rare cases of squamous cell carcinoma have reportedly arisen from lichen planus on both the skin and mucous membranes. While squamous cell carcinoma has been more commonly reported with oral lichen planus, Knackstedt and colleagues reported a series of 38 cases of squamous cell carcinoma resulting from hypertrophic cutaneous lichen planus.12 The most frequent sequela of lichen planus is chronic post-inflammatory hyperpigmentation at the site of prior skin lesions.

In Conclusion

Lichen planus is a self-limited autoimmune disease with characteristic features but numerous clinical variations. The exact etiology of lichen planus is unknown but contributing factors range from genetic predisposition and emotional stress to localized skin disease like herpes zoster and certain medications. The Koebner phenomenom is the development of skin lesions in areas of skin trauma and commonly arises in lichen planus.

This case highlights the development of lichen planus at a surgical site secondary to skin trauma. The diagnosis of lichen planus is often clinical but a punch biopsy can aid in diagnosis. Topical corticosteroids are the first-line treatment of lichen planus but other modalities are available for more severe, widespread and hypertophic lesions. There are few sequelae of lichen planus other than hyperpigmentation and recurrence.

Dr. Hoffman is the Medical Director of the Orthopedic Clinic and an Attending Physician within the Department of Orthopedics at Denver Health Medical Center. She is an Assistant Professor within the Department of Orthopedics at the University of Colorado School of Medicine.


1.    Wagner G, Rose C, Sachse MM. Clinical variants of lichen planus. J Dtsch Dermatol Ges. 2013;11(4):309-319.
2.    Shengyuan L, Songpo Y, Wen W, Wenjing T, Haitao Z, Binyou W. Hepatitis C virus and lichen planus: a reciprocal association determined by a meta-analysis. Arch Dermatol. 2009;145(9):1040-1047.
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8.    Cribier B, Frances C, Chosidow O. Treatment of lichen planus. An evidence-based medicine analysis of efficacy. Arch Dermatol. 1998;134(12):1521-1530.
9.    Lozada-Nur F, Miranda C. Oral lichen planus: topical and systemic therapy. Semin Cutan Med Surg. 1997;16(4):295-300.
10.    Pavlic V, Vujic-Aleksic V. Phototherapy approaches in treatment of oral lichen planus. Photodermatol Photoimmunol Photomed. 2014;30(1):15-24.
11.    Fazel N. Cutaneous lichen planus: A systematic review of treatments. J Dermatolog Treat. 2015;26(3):280-283.
12.    Knackstedt TJ, Collins LK, Li Z, Yan S, Samie FH. Squamous cell carcinoma arising in hypertrophic lichen planus: a review and analysis of 38 cases. Dermatol Surg. 2015;41(12):1411-1418.

Dermatology Diagnosis
Kristine Hoffman DPM, FACFAS
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