Contact allergy in atopic dermatitis: A prospective study on prevalence, incriminated allergens and clinical insights.

BACKGROUND: The relationship between atopic dermatitis (AD) and allergic contact dermatitis (ACD) is a matter of debate. OBJECTIVES: The purpose of our study is to assess the frequency of ACD in patients with AD, the incriminated allergens and the potential risk factors. METHODS: This is a prospective study, including cases of AD diagnosed based on Hanifin and Rajka's criteria. All patients were patch tested to the European baseline series and corticosteroid series. RESULTS: Ninety-three patients were included. Fifty-six patients (60.2%) had positive patch test results of which 71.4% were relevant. The most frequent allergens were: textile dye mix (24.7%), nickel (20.4%), cobalt (12.9%), isothiazolinone (8.6%), quanterium 15 (4.3%) and balsam of Peru (4.3%). Chromium, fragrance mix I, fragrance mix II and PTBP were positive in three cases (3.2%). Two cases of allergy to corticoids were identified. Facial involvement and duration of AD were significantly associated with contact sensitization (p = 0.04 and p = 0.005, respectively). Avoidance of relevant allergens resulted in a statistically significant decrease in SCORAD (p < 0.001). CONCLUSIONS: ACD remains an important co-morbidity of AD. We observed a high frequency of ACD to textile dyes, isothiazolinones and fragrances. Avoidance of relevant allergens has resulted in an improvement of patients' skin symptoms.

Acquired Ichthyosis Revealing Lymphocytic Colitis.

A 69-year-old patient with no personal or family history of ichthyosis consulted our dermatology department for diffused cutaneous xerosis with intense pruritus evolving for 3 weeks. Physical examination revealed diffused ichthyosis of large polygonal fine scales on the skin without erythema (Figure 1). The lesions spared the face. Examination of the mucous membranes, hair, and nails revealed no abnormalities. There was no fever or adenomegaly. A skin biopsy revealed an orthokeratotic hyperkeratosis with thinning of granular layer (Figure 2). The initial diagnosis of acquired ichthyosis was maintained. The patient also reported a change in bowel habits since 2 weeks with watery, non-bloody diarrhea and mild steatorrhea. His laboratory investigations presented low serum vitamin B12 level, mild anemia, hypoalbuminemia, and fecal leukocytes; however, antinuclear antibodies, perinuclear anti-neutrophil cytoplasmic antibodies (pANCA), rheumatoid factor, and complement components C3 and C4 were normal. A colonoscopy performed was also normal without any abnormalities. Colon biopsies revealed histologic aspects of lymphocytic colitis with more than 20% increase in lymphocytes in the surface epithelium of colorectal mucosa. Laboratory investigations excluded neoplasia, hemopathies, or autoimmune-associated diseases. The patient was treated with salazopyrin with a remarkable lessening of diarrhea and cutaneous manifestations within 4 weeks (Figure 3).

A Mass on the Sole Revealing a Giant-Cell Tumor of the Tendon Sheath.

A 61-year-old woman presented with a 3-year history of painless soft-tissue mass on the right sole. The patient reported gradual growth, with a rapid increase in size over the past few months, leading to difficulty in walking. She had no history of past trauma. Examination revealed a 4-cm ovoid mass located over the ball of the foot. It was firm in consistency, with well-defined margins, a smooth surface, and an overlying normal skin (Figure 1). An ultrasound image revealed an eccentric, hypoechoic, nonvascular subcutaneous lobular mass. A magnetic resonance imaging (MRI) of the foot revealed a well-defined mass arising from the flexor tendon sheath of the right foot. The lesion was heterogeneously hyperin-tense on T1- and T2-weighted images with an avid contrast enhancement. All of the surrounding soft tissues indicated normal signal intensity patterns. There was no associated bony destruction. Histopathologic examination after complete excision of the mass established a well-circumscribed lesion composed of osteoclast-like giant cells and mononuclear cells in a hyalinized stroma, consistent with a giant cell tumor of the tendon sheath (GCT-TS) (Figure 2). There was no recurrence during a 6-month follow-up period (Figure 3).

Contact Sensitization in Pediatric Population With Atopic Dermatitis: A Retrospective Study of 80 Patients.

OBJECTIVE: This study aimed to evaluate the frequency of allergic contact dermatitis among children with atopic dermatitis (AD), the most common sensitizer, and the associated risk factors. METHODS: This retrospective study included children with AD who underwent patch testing at our dermatology department between 2005 and 2021. RESULTS: Eighty patients were included. The average age was 77.6 months (4 months-17 years), divided as follows: children (76.3%), infants (11.3%), and teenagers (10%). The sex ratio (M/F) was 1.35. Thirty-two patients (40%) had positive patch test results. Allergic contact dermatitis was significantly more frequent among patients with severe AD (40.6%) than among those with moderate or mild AD (16.7%, P = 0.017). The most frequent allergens were nickel sulfate (23.7%), cobalt chloride (12.5%), potassium dichromate (8.7%), textile dyes (6.2%), and lanolin (5%). CONCLUSIONS: Contact allergies are a common problem in children with AD. They seem to be at risk of sensitization to certain allergens mainly metals and components of skincare products. Patch testing should be performed whenever allergic contact dermatitis is suspected and in cases of severe AD.

Scabies surrepticius: An uncommon presentation of a common dermatosis.

We report an atypical presentation of a common disease to highlight the importance of making a correct diagnosis of scabies surrepticius in front of any itchy dermatosis especially in elderly patients. The misdiagnosis of this disease results in extensive infestation, especially with the use of corticosteroids.