Pigmented contact dermatitis secondary to benzyl salicylate

Differential diagnosis of contact dermatitis: A practical-approach review by the EADV Task Force on contact dermatitis

The diagnosis of eczema ('dermatitis') is mostly clinical and depends on the clinical history and exploratory objective findings (primary lesions, patterns). Contact dermatitis remains as an important condition in the group of eczematous disorders, with important socioeconomic and occupational relevance. Although irritant and allergic contact dermatitis have a different pathogenesis, both are characterized by a rather typical morphology, are triggered by external factors and tend to occur primarily in the area of contact with the exogenous agent. In addition, allergic and irritant dermatitis may also co-exist. The importance of diagnosing contact dermatitis, especially when allergic in nature, is both due to the possibility of avoiding the trigger, and due to its role in aggravating other skin conditions. Nevertheless, the heterogeneity of clinical presentations in daily practice may pose an important challenge for the suspicion and correct diagnosis of contact dermatitis. Furthermore, other conditions, with different pathogenesis and treatment, may clinically simulate contact dermatitis. The Task Force aims to conduct a review of the unifying clinical features of contact dermatitis and characterize its main clinical phenotypes, and its simulators, in order to contribute to an early suspicion or recognition of contact dermatitis and enable a correct differential diagnosis.

Pigmented contact dermatitis: A brief review

Hyperpigmentation is one of the common pigmentary complaints that brings the patient to dermatology services. Though there are multiple etiologies for hyperpigmentation, pigmented contact dermatitis (PCD) remains a common diagnosis. The cosmetics containing dyes, preservatives, fragrances, bactericidal, emulsifiers/surfactants, and vehicles are the potential sources, and paraphenylenediamine, benzyl salicylate, brilliant lake red R, thiomersal and gallate mix are some of the most commonly implicated allergens.

The clinical manifestation includes diffuse or patchy brown to blue-black pigmentation of the cheeks, the outer surface of ears, preauricular region, temporal area, nape of the neck, and upper back. Patch testing plays a pivotal role in the diagnosis of PCD and the testing series has to be selected according to the representative population. Given the chronicity of the disease, counseling patients against the use of cosmetics is challenging as the pigmentation tends to persist for longer durations inspite of stopping cosmetics. The pillars of treatment in PCD include recognition of the culprit allergen and preventing further exposure along with pharmacological therapy. This review provides a brief overview and an insight into the etiopathogenesis and management of PCD.

Sensitization to benzyl salicylate and other allergens in patients with frontal fibrosing alopecia

BACKGROUND

Contact sensitization is frequent among patients with frontal fibrosing alopecia (FFA) (52%-76%).

OBJECTIVE

To evaluate the frequency of sensitization/photosensitization in an FFA population.

METHODS

A population of FFA patients were patch tested (Spanish Contact Dermatitis Research Group [GEIDAC] baseline; cosmetic and fragrance series), and photopatch tested (sunscreen series).

RESULTS

Thirty-six patients (mean age: 64.6 years; 35/36: women) were studied. A history of dermatitis was recorded in 69.4% (frequently involving the face). Overall, 80.5% patients showed positive patch-test reactions. The most frequently positive allergens were nickel sulfate (25%), benzyl salicylate (22%), gallates (16.6%), propolis (16.6%), and limonene hydroperoxides (13.8%). Benzyl salicylate was likely relevant to the dermatitis (labeled on personal care products and most patients reporting clinical improvement with allergen avoidance). Patch tests with sunscreens showed positive reactions to 11 materials (five patients). Photopatch tests were positive in one case.

CONCLUSION

We speculate a possible relationship between sensitization to benzyl salicylate and FFA. Hypothetically, the most likely explanation is that sensitization to benzyl salicylate involving FFA patients is a consequence of increased exposure to it. It is unclear whether allergen avoidance may impact the prognosis of alopecia. However, it seems to significantly improve the patients´ quality of life by lessening dermatitis and pruritus.

Multispectral Dermatoscopic Features of Chemical Leucoderma with Pigmented Contact Dermatitis

Chemical leukoderma is characterized by pigment loss on constant exposure to chemical agents. Its association with pigmented contact dermatitis is rare. Here, we report a 40-year-old female presenting with depigmented macule with surrounding hyperpigmentation over the upper forehead. We used a multispectral dermatoscope by which decreased pigment network was better visualized with blue light, and gray granular dots were better appreciated with yellow light. Shorter wavelengths delineate epidermal features better whereas longer wavelengths highlight dermal features in multispectral dermatoscopy.