Clustered papulonodular lesions in an infant.

Non-Langerhans cell histiocytosis is a collective term encompassing a vast group of benign proliferative disorders of histiocytes, macrophages and dendritic cells that do not meet the criteria of Langerhans cell histiocytosis. We describe a case of juvenile xanthogranuloma with an unusual clustered distribution.

Severe epidermolysis bullosa/Kindler syndrome-like phenotype of an autoinflammatory syndrome in a child.

A 5-year-old boy presented with generalized cutaneous erosions, severe scarring, depigmentation and contractures affecting major joints. The lesions had initially affected his ears, nose, feet, and the genital and ocular mucosa, leading to significant depigmentation, scarring, contractures and mutilation. The whole of the trunk and limbs were involved at the time of presentation, with the exception of some islands of spared skin on the proximal thighs, legs, nipples and external genitalia. Electron microscopy revealed a split in the sublamina densa with the absence of anchoring fibrils, suggestive of dystrophic epidermolysis bullosa (EB). Immunofluorescence antigen mapping demonstrated a broad reticulate pattern of staining with collagen IV, VII, and laminin 332 in the floor of the blister, suggestive of Kindler syndrome. Next-generation sequencing revealed a de novo heterozygous missense mutation (a variant of unknown significance) in exon 22 of the phospholipase-C gamma 2 gene (PLCG2), which resulted in a substitution of serine by asparagine at codon 798 (p.Asp798Ser), a result that was validated using Sanger sequencing. The child was diagnosed with PLCG2-associated antibody deficiency and immune dysregulation (PLAID)/autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) syndrome. The cutaneous and corneal erosions, inflammation and scarring of this magnitude, and the eventual result of death have not been described previously for the PLAID/APLAID spectrum previously. In conclusion, this was an unusual acquired autoinflammatory severe EB-like disease that may be associated with de novo PLCG2 mutation.

Contact sensitization to hair colours in acquired dermal macular hyperpigmentation: results from a patch and photo-patch test study of 108 patients.

BACKGROUND: Acquired dermal macular hyperpigmentation (ADMH) is an umbrella term including lichen planus pigmentosus, erythema dyschromicum perstans and pigmented contact/cosmetic dermatitis. OBJECTIVE: To establish contact sensitization to hair colours as an aetiological factor for ADMH. METHODS: Detailed clinical examination, skin biopsies, and patch and photo-patch testing with Indian standard series and patient's own cosmetic products were performed. RESULTS: Thirty-nine (36.1%) patients were found to demonstrate a positive patch/photo-patch test with 35/39 reacting to their own products (all were hair colours) and 16/39 reacting to antigens from commercial series (commonly paraphenylenediamine). Fourteen patients developed delayed hyperpigmentation on positive patch-test sites at 1 month. Higher mean age, symptomatic pigmentation (pruritus, burning and photosensitivity), hair margins involvement (outer surface, helix and lobule of ear; temples and preauricular area), ill-defined lesions, epidermal atrophy and epidermal melanization extending >3 layers were significantly common in patch-test-positive patients. Well-defined lesions, perioral involvement and associated lichen planus were clinical pointers towards patch-test negativity. CONCLUSION: Index study exemplifies that patch-test results have distinct clinical and histopathological correlates in ADMH. Hair dye contact sensitization appears to be an important aetiological factor in about one-third patients presenting with ADMH.