Pitted keratolysis - a study of various clinical manifestations.

BACKGROUND: Pitted keratolysis (PK) is a common bacterial infection of skin characterized by noninflammatory superficial pits. Very few studies have focused on variations in clinical manifestations of PK. We conducted this study so that diagnosis of this treatable condition is not missed when it presents in an uncommonly perceived way. AIMS AND OBJECTIVES: Assessment of PK patients for various sites and morphologies. MATERIALS AND METHODS: A total of 30 patients with PK were assessed for various sites and morphologies. Bacterial and fungal cultures along with histopathology were performed. RESULTS: Of 30 patients, 24 were females. Hyperhidrosis and malodour were the most common symptoms. Interdigital interface skin of the toes was the first site affected in most patients. Plantar skin was affected in all patients with involvement of interface skin of the toes in 29 patients. Other sites affected were palms, finger web spaces, nonglabrous skin, paronychium, and nail. Other than classical pits, scaly crusted inflammatory lesions with post-inflammatory hyperpigmentation (PIH) were noted. Associated keratoderma was also reported in some patients. DISCUSSION: The presence of hyperhidrosis, malodour, and plantar lesions is consistent with previous studies. Interface skin between toes as the first site affected, involvement of toe web spaces, and associated keratoderma have been reported rarely. However, female preponderance, involvement of finger web spaces, nonglabrous skin, paronychium, nail changes, the presence of inflammation with crusting, and PIH have never been reported previously. CONCLUSION: PK can involve web spaces, nonglabrous skin, and paronychium, and can cause nail changes. The lesions can be inflammatory with crusting and PIH.

Identification of Helicobacter pylori in skin biopsy of prurigo pigmentosa.

A 23-year-old Chinese man presented with a 3-year history of a pruritic eruption. On examination, pink urticarial papules associated with hyperpigmented reticulated patches were noted on his neck, back, and upper chest. Histopathology revealed vacuolar interface dermatitis and numerous gram-negative rods within a dilated hair follicle. The organisms were reactive with anti-Helicobacter pylori immunohistochemisty. The histologic findings and clinical presentation support the diagnosis of prurigo pigmentosa. Additional testing demonstrated a positive urease breath test and serum H. pylori IgG antibodies. The patient was referred to gastroenterology and treated with appropriate antibiotics. After treatment, esophagogastroduodenoscopy revealed chronic gastritis without evidence of H. pylori infection and his skin showed reticulated hyperpigmented patches without evidence of active inflammatory papules. Although previous reports have associated prurigo pigmentosa to H. Pylori gastritis, this is the first report of H. pylori organisms identified in a skin biopsy of prurigo pigmentosa.

Antimelanogenic and antioxidative properties of Bifidobacterium bifidum.

Various skin hyperpigmentation disorders consist in accumulation and overproduction of melanin. In this report, we investigated the melanogenesis inhibitory and antioxidant effects of Bifidobacterium bifidum culture filtrate. The results revealed that B. bifidum culture filtrate effectively suppresses murine tyrosinase activity and decreases the amount of intracellular melanin in a dose-dependent manner. Additionally, the bacterial culture filtrate-scavenged DPPH and ABTS radicals, and shows potent-reducing power in a dose-dependent pattern. Our results expand the application of B. bifidum culture filtrate in the development and research of skin-whitening ingredients.

Longitudinal melanonychia of the toenails with presence of Medlar bodies on biopsy.

A 9-year-old girl presented with a 2-year history of pigmented streaks on her second right toenail as well as on her fourth and fifth left toenails. The patient was otherwise asymptomatic with no other physical findings. Owing to parental concern, a biopsy was performed, which revealed numerous bacteria as well as Medlar bodies overlying the nail bed with no evidence of a nevomelanocytic lesion. To our knowledge, this is the first report of Medlar bodies causing pigmented streaks in the toenails.