Image Challenge of the Week! – Answer

lichen planus 2
Am Fam Physician. 2011 Jul 1;84(1):53-60.

Click here for original image challenge

Diagnosis:

Lichen planus

Pearl:

The most typical form of lichen planus can be described by the “six Ps”: purple, pruritic, polygonal, planar, papules, and plaques.

Discussion:

Lichen planus is an inflammatory condition that commonly affects the skin but may also involve the oral mucosa, genital mucosa, nails, and scalp. Its distribution is typically symmetric and distributed along the wrists, flexural aspects of the arms and legs, and the lower back. They often develop along areas of trauma (Koebner’s phenomenon).

The etiology is unknown but there appears to be an increased incidence in patients with hepatitis C. Several drugs can cause lichenoid eruptions. Thus, a reconciliation of recent medications must be performed in suspected cases. The table below lists several drugs implicated in such reactions. The bolded drugs are the ones most frequently implicated.

Group of drug
Antimicrobial substances Aminosalicylate sodium, ethambutol, griseofulvin, ketoconazole, streptomycin, tetracycline, trovafloxacin, isoniazid
Antihistamines (H2-blocker) Ranitidine, roxatidine
Antihypertensives/antiarrhythmics ACE-inhibitors (captopril, enalapril), doxazosin, beta blockers (propranolol, labetalol, sotalol), methyldopa, prazosin, nifedipine, quinidine
Antimalarial drugs Chloroquinehydroxychloroquine, quinine
Antidepressives/antianxiety drugs/antipsychotics/anticonvulsants Amitriptyline, carbamazepine, chlorpromazine, levomepromazine, methopromazine, imipramine, lorazepam, phenytoin
Diuretics Thiazide diuretics (chlorothiazide and hydrochlorothiazide), furosemide, spironolactone
Antidiabetics Sulfonylureas (chlorpropamide, glimepiride, tolazamide, tolbutamide, glyburide)
Metals Gold salts, arsenic, bismuth, mercury, palladium, lithium
Nonsteroidal-antiinflammatory drugs (NSAIDs) Acetylsalicylic acid, benoxaprofen, diflunisal, fenclofenac, flurbiprofen, ibuprofen, indomethacin, naproxen, sulindac
Proton pump inhibitors Omeprazole, lansoprazole, pantoprazole
Lipid lowering drugs Pravastatin, simvastatin, gemfibrozil
Tumor necrosis factor-alpha antagonists Infliximab, adalimumab, etanercept, lenercept
Varia Allopurinol, bleomycin, cinnarizine, cyanamide, dapsone, hydroxyurea, hepatitis B-vaccine, imatinib, immunoglobulins, interferon alfa, l-thyroxin, levamisole, mesalamine, methycran, penicillamine, procainamide, pyrimethamine, pyrithioxine, quinacrine, sildenafil, sulfasalazine, terbinafine, trihexyphenidyl, ursodeoxycholic acid

 

https://www.uptodate.com/contents/image?imageKey=DERM%2F83762&topicKey=DERM%2F5662&rank=1~144&source=see_link&search=lichen%20planus

It is diagnosed by its characteristic appearance as above “the six Ps” and by biopsy if clarification is needed. The differential diagnosis includes: eczema, lichen simplex chronicus, pityriasis rosea, prurigo nodularis, psoriasis, and syphilis,

Treatment options lack large randomized controlled trials to support practice. However, potent topical corticosteroids are often used early for localized lesions. Systemic oral corticosteroidscan be used for more generalized lesions.

References:

Am Fam Physician. 2011 Jul 1;84(1):53-60.

Am Fam Physician. 2000 Jun 1;61(11):3319-3324.

UpToDate