Mona Abdel-Halim

The purpose of this study was to evaluate the efficacy of fractional carbon dioxide laser use in the treatment of mature burn scars. This was an uncontrolled, open-label clinical trial. The setting for this study was Dermatology Department at Cairo University in Cairo, Egypt. Twenty patients with mature burn scars were included in the study. Three fractional carbon dioxide laser sessions were given, 4 to 8 weeks apart. Primary outcome was measured using two scar scales, the Vancouver Scar Scale and the Patient and Observer Scar Assessment Scale. Secondary outcomes included evaluation of collagen and elastic fibers using routine hematoxylin and eosin, Masson's trichrome, and orcein stains. Outcomes were measured two months after the last laser session. Both Vancouver Scar Scale and Patient and Observer Scar Assessment Scale showed significant reduction following treatment (<0.001). Scar relief and pliability improved most followed by vascularity. Pigmentation improved the least. Percent improvement in Patient and Observer Scar Assessment Scale patients' overall assessment was 44.44 percent. The pattern and arrangement of collagen and elastic fibers showed significant improvement (<0.001, =0.001, respectively), together with significant improvement in their amounts (=0.020, <0.001, respectively). No significant correlation existed between clinical and histopathological/histochemical scores. Side effects and complications were mild and tolerable. Fractional carbon dioxide laser use is an effective and safe method for treating burn scars with a significant change in the opinion of the patients about their scar appearance.

Hypopigmented interface T-cell dyscrasia (HITCD) is a distinct form of lymphoid dyscrasia that may progress to hypopigmented mycosis fungoides (HMF). We compared both diseases as regards their CD4/CD8 phenotype and expression of granzyme B and tumor necrosis factor-alpha (TNF-α) and how these are affected by narrow-band UVB (nb-UVB). The study included 11 patients with HITCD and 9 patients with HMF. They received nb-UVB thrice weekly until complete repigmentation or a maximum of 48 sessions. Pretreatment and posttreatment biopsies were stained using anti CD4, CD8, TNF-α, and granzyme B monoclonal antibodies. Epidermal lymphocytes were CD8 predominant in 54.5% and 66.7% of HITCD and HMF cases, respectively, whereas dermal lymphocytes were CD4 predominant in 63.6% and 66.7%, respectively. Significantly, more dermal infiltrate was encountered in HMF (P = 0.041). In both diseases, granzyme B was only expressed in the dermis, whereas TNF-α was expressed both in the epidermis and dermis. No difference existed as regards the number of sessions needed to achieve repigmentation or cumulative nb-UVB dose reached at end of study. (P > 0.05). Narrow-band UVB significantly reduced only the epidermal lymphocytes in both diseases (P ≤ 0.05) with their complete disappearance in 8 (72.7%) HITCD and 6 (66.7%) HMF cases. In both diseases, nb-UVB did not affect granzyme B or TNF-α expression (P > 0.05). In conclusion, both diseases share the same phenotype, with HITCD being a milder form of T-cell dysfunction. In both diseases, epidermal lymphocytes are mainly CD8-exhausted cells lacking cytotoxicity, whereas dermal cells are mostly reactive cells exerting antitumor cytotoxicity. Tumor necrosis factor-alpha mediates hypopigmentation in both diseases and prevents disease progression. Repigmentation after nb-UVB in both diseases occurs before and independently from disappearance of the dermal infiltrate.

BACKGROUND/OBJECTIVES: Pityriasis lichenoides chronica (PLC) lesions are reported to subside with post-inflammatory hypopigmentation (PIH); hence, the most widely perceived nature of hypopigmented macules in PLC is PIH. However, to the best of our knowledge, no studies describing histopathological findings in these lesions are reported in literature. The aim of this study is to evaluate the hypopigmented lesions encountered in PLC patients and to shed light on their histopathological features.

METHODS: A cross-sectional observational study included twenty-one patients with PLC recruited in a period of twelve months. Clinical characteristics of each patient were collected. A skin biopsy from hypopigmented lesions whenever present was taken and assessed with routine haematoxylin and eosin stain.

RESULTS: Seventeen patients (81%) were less than 13 years old. Most patients (85.7%) demonstrated diffuse distribution of lesions. Hypopigmented lesions were present on the face in 12 (57.14%) patients. Histopathologically, hypopigmented lesions showed features of post-inflammatory hypopigmentation in 19% of patients, residual PLC in 52.4% and active PLC 28.6% of patients.

CONCLUSION: Hypopigmented lesions in PLC were noted mainly in younger ages, histopathologically they may show features of active or residual disease, beyond post-inflammatory hypopigmentation. Consequently active treatment for patients presenting predominantly with hypopigmented lesions could be required to control the disease.