RESUMEN
Background: It is hypothesized that scalp allergic contact dermatitis (ACD) in women is commonly mistaken for other disorders due to overlapping symptoms and unique clinical presentations. Objective: This study reviews the potential underdiagnosis and misdiagnosis of scalp ACD and explores ways to improve diagnostic accuracy. Methods: This study conducted an extensive literature review to identify diagnostic challenges, common misdiagnoses, and diagnostic approaches for scalp ACD, focusing on standard versus targeted patch testing techniques. Results: Scalp ACD, often misdiagnosed as seborrheic dermatitis due to similar symptoms, has atypical presentations such as hair thinning, hair loss, and erythematous lesions affecting neighboring regions. Trichoscopy can help distinguish scalp ACD, identifying its patchy distribution of thin white scales, in contrast to the yellow scaling of seborrheic dermatitis. Standardized patch testing further contributes to diagnostic errors, with a study reporting 83% of patients who tested negative with standardized patch tests were positive when using their personal products. Individualized patch testing is more effective in identifying causative allergens and accurately diagnosing scalp ACD. Limitations: It is a retrospective review. Conclusion: Several factors contribute to scalp ACD's misdiagnosis for conditions such as seborrheic dermatitis. The significant discrepancy in ACD detection rates between personalized and standardized patch tests in women emphasizes the importance of using patient-specific products in diagnostic testing. Incorporating scalp ACD more readily into one's differential, employing individualized patch testing with trichoscopy, and accounting for neighboring symptomatic areas are all crucial elements in improving diagnostic accuracy for scalp ACD in women.
RESUMEN
Seborrheic Dermatitis (SD) is a chronic and relapsing inflammatory condition accompanied by erythema, flaking and itching. Dandruff is a milder form of SD. Selenium disulfide (SeS2) is beneficial in both conditions. OBJECTIVES: to assess the efficacy of SeS2-based shampoo in dandruff/SD. MATERIALS & METHODS: an international, multicenter, observational study was conducted in 1407 adult subjects. SeS2- based shampoo was used 2 to 3 times per week for 4 weeks. Clinical efficacy criteria included improvement of hair, flaking, erythema and irritation on a scale from 0 to 5; investigator satisfaction was assessed at month 3 from 0 to 10. The subjects rated the impact of their hair problem (0 to 5), efficacy and satisfaction with SeS2-based shampoo at month 3. Tolerance was assessed throughout the study. RESULTS: At baseline, 68.2% had a flake severity score of 3-5, 49.9% an erythema severity score of 3-5, and 46.2% an irritation severity score of 3-5; 28.2% were bothered and 41.5% were very bothered. At study end, SD/D had at least clearly improved in 89.6% of subjects. All clinical signs had significantly (p<0.001) improved. 95.6% of subjects reported less pruritus. Significantly fewer (15.4%, p<0.0001) subjects were still bothered. The overall subject satisfaction score was 8.9±1.4; 97.6% of investigators were satisfied or very satisfied. Tolerance was good or very good in 98.8% of subjects. CONCLUSION: A SeS2-based shampoo applied 2 to 3 times per week is efficient and well tolerated in dandruff and SD.