Oral Lichen Planus and Allergy to Dental Amalgam Restorations
Oral lichen planus (OLP) is a chronic, persistent, inflammatory condition affecting the buccal, lingual, and gingival mucosa. Of the many potential pathophysiologic factors triggering this condition, a contact hypersensitivity reaction to dental restorative materials has remained controversial. In this prospective nonrandomized study, Laeijendecker et al demonstrate that in patients with OLP lesions in close contact with amalgam fillings and no concomitant cutaneous lichen planus, contact allergy plays a significant pathophysiologic role. In addition, partial or complete removal of dental amalgam restorations following positive patch test reactions to ammoniated mercury, metallic mercury, or amalgam produced a significant therapeutic benefit in nearly all patients.
Response of Oral Lichen Planus to Topical Tacrolimus in 37 Patients
Oral lichen planus (OLP) is a noninfectious, chronic inflammatory disease of the oral mucosa characterized by white striations, papules, plaques, erythema, erosions, and blisters that may be quite disabling. Symptomatic OLP may prove recalcitrant to the numerous topical and systemic therapeutic options that exist. In this retrospective survey, Byrd et al report their long-term experience with topical tacrolimus in 40 patients with OLP. A twice-daily regimen was safe and effective in most patients, and long-term use (more than 1 year) did not result in any serious adverse effects. Although topical tacrolimus rarely results in complete remission of OLP, it has proven effective in controlling the disease.
Oral Alitretinoin (9-cis-Retinoic Acid) Therapy for Chronic Hand Dermatitis in Patients Refractory to Standard Therapy
Chronic hand dermatitis affects up to 10% of the population and is accompanied by physical symptoms that may be a source of occupational disability and psychological distress. Topical corticosteroids are the first line of therapy, but some refractory cases show no response to this standard regimen. Systemic therapy or photochemotherapy has been successful in some refractory cases, but the use of these regimens is limited by inconvenience or adverse effects. In this multicenter, randomized, double-blind, placebo-controlled prospective study of 319 patients with moderate or severe refractory chronic hand dermatitis, oral alitretinoin was well tolerated and led to a significant and dose-dependent improvement in disease status. The mechanism by which alitretinoin exerts these therapeutic effects remains unclear and unexplainable by any particular retinoid receptor binding pattern.
Comparison of Oral Psoralen–UV-A With a Portable Tanning Unit at Home vs Hospital-Administered Bath Psoralen–UV-A in Patients With Chronic Hand Eczema
Hand dermatitis tends to run a long-lasting relapsing course. Water is a major exogenous factor contributing to this disease, while an atopic diathesis is an endogenous factor. In cases refractory to topical therapies, psoralen–UV-A (PUVA) offers an excellent therapeutic option in which the psoralens may be administered either orally or locally followed by UV-A irradiation. A major limitation of this therapy is convenience. In this open-label, randomized controlled trial, van Coevorden et al compared hospital-administered trioxsalen bath PUVA with oral methoxsalen capsule PUVA and a simple portable commercial facial tanning unit. The home regimen proved as effective as the hospital-administered regimen at substantially lower travel costs and less time off work for patients.
Psoriasis Triggered by Toll-like Receptor 7 Agonist Imiquimod in the Presence of Dermal Plasmacytoid Dendritic Cell Precursors
Toll-like receptors (TLRs) are well-conserved transmembrane proteins that serve as major pattern recognition receptors of the innate immune system. Imiquimod is a selective TLR7 agonist with innate antiviral and antitumoral effects attributable to the induction of type I interferon. In this case report, plaque-type psoriasis was clinically exacerbated by topical imiquimod therapy, accompanied histologically by large numbers of plasmacytoid dendritic cells that may represent the type 1 interferon–producing target cells in psoriasis.
Topical imiquimod treatment induces clinical aggravation and spreading of a psoriatic plaque misdiagnosed as Bowen disease. Clinical course of a solitary psoriatic plaque during a 10-week topical treatment with 5% imiquimod. A, Before treatment; B, at week 6 of treatment; and C, at week 10 of treatment. Ruler measures in centimeters.