Oral lichenoid lesions: the greatest challenge is a correct diagnosis

OLLs are often triggered by medication or are a concomitant symptom of underlying inflammatory diseases, and are very similar to oral lichen planus. Differentiation and finding triggering factors is challenging.

Differentiation between lichenoid lesions and lichen planus in the oral cavity is often difficult

Oral lichenoid lesions (OLL) are very similar in appearance to oral lichen planus (OLP) but differ in etiology. OLLs are often triggered by medication or are a concomitant symptom of underlying inflammatory diseases. The differentiation from OLP and finding the triggering factor is often a great challenge.

Compared to other symptoms or side effects, OLLs rarely occur in everyday clinical practice, but they are often a great burden for those affected due to severe pain and restrictions in everyday life. OLLs are one of the main differential diagnoses to the more frequently observed OLP and can be triggered by a variety of factors.

In an Austrian study, more than 300 patients with inflammatory skin diseases were examined for OLL. The evaluation showed that women are affected twice as often as men and OLL can occur regardless of age. In total, 47 different underlying diseases were present in the analyzed patient group. Some of the underlying diseases included pemphigus vulgaris, bullous pemphigoid, systemic or discoid lupus erythematosus, etc.

Numerous triggers make correct diagnosis difficult

Diagnosis is a major challenge for several reasons. First, many inflammatory skin diseases are similar in appearance, especially at the beginning of the disease. In addition, the relatively poor visibility of the oral cavity makes it difficult to assess the oral lesions and also to carry out appropriate examinations such as biopsies. Often only minor differences can be found histologically.

Nevertheless, the biopsy is the method of choice for a more precise diagnosis in combination with a detailed medical history - ideally in interdisciplinary cooperation with colleagues from dermatology, pathohistology, and dentistry. In addition, according to a suspected diagnosis, direct (indirectly is less effective) immunofluorescence, ELISA or other histological examinations can provide further indications.

NSAR, antihypertensives & Co. as trigger factors

In addition to the diseases mentioned above, drugs are often the cause of OLL. The most common trigger factors are the following three groups of active substances:

But similar changes in the oral mucosa have also been observed when taking biologicals, statins, and other drugs. The great difficulty in detecting the triggering drug is that OLLs occur rather variably over time after the start of the intake -and this can last from weeks to several months.

In addition, many of the patients in this group take several drugs at the same time. An important indication may be the occurrence of unilateral, singular lesions; this morphology was typically observed in drug-induced OLL.

In addition to drugs, foreign materials in the oral cavity, such as dentures or amalgam fillings, can also trigger OLL. In this case, the removal of the trigger factor is usually sufficient as treatment.

Recommendations for clinical daily practice

Dr. med. Igor Vujic - Clinical Centre Vienna Joint Practice, "Mucosal lichenoid lesions", EADVirtual 2020, 30.10.2020