Meiotic sex chromosome inactivation (MSCI) during spermatogenesis is characterized by transcriptional silencing of genes on both the X and Y chromosomes in mid to late pachytene spermatocytes1. MSCI is believed to result from meiotic silencing of unpaired DNA because the X and Y chromosomes remain largely unpaired throughout first meiotic prophase2. However, unlike X-chromosome inactivation in female embryonic cells, where 25–30% of X-linked structural genes have been reported to escape inactivation3, previous microarray4- and RT-PCR5-based studies of expression of >364 X-linked mRNA-encoding genes during spermatogenesis have failed to reveal any X-linked gene that escapes the silencing effects of MSCI in primary spermatocytes. Here we show that many X-linked miRNAs are transcribed and processed in pachytene spermatocytes. This unprecedented escape from MSCI by these X-linked miRNAs suggests that they may participate in a critical function at this stage of spermatogenesis, including the possibility that they contribute to the process of MSCI itself, and/or that they may be essential for post-transcriptional regulation of autosomal mRNAs during the late meiotic and early postmeiotic stages of spermatogenesis.

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Prurigo pigmentosa (PP) is a rare inflammatory dermatosis of unknown cause characterized by a predominantly truncal eruption of pruritic erythematous papules in a reticular pattern, resolving with hyperpigmentation. PP is twice as common in girls and women, and the mean age at onset is 25 years. Diagnosis of PP is challenging and is aided by characteristic histopathologic findings. We report a case of PP in a 17-year-old white boy. The eruption arose during strict adherence to a ketogenic diet.

Multiple sensory modalities were found to be abnormal in patients with erythromelalgia, with the commonest clinical abnormality being isolated heat-pain abnormality. These findings lend support to the notion that neuropathy underlies the clinical diagnosis of erythromelalgia. Future studies will explore the nature of the relationship between these sensory abnormalities and the clinical features of erythromelalgia.

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A 28-year-old Hispanic woman who was three weeks postpartum presented with a 5-day history of pruritic rash and a 2-day history of arthralgia and sore throat. Her pregnancy was complicated by pre-eclampsia at term, and she had a Cesarean delivery. The rash first appeared on the shoulders and spread centrifugally to the arms, thighs, and legs. Arthralgia began in the small joints of the hands and progressed to involve the wrists and shoulders.At presentation, the rash involved the extensor arms and legs with monomorphous, edematous, pink papules (3-4 mm) in a linear configuration (Fig. 1). The trunk was spared. Biopsy specimens were obtained from lesional and perilesional skin on the left arm. Direct immunofluorescence performed on the perilesional specimen was negative for autoimmune blistering disorders. Microscopic examination of a representative lesion showed prominent epidermal spongiosis, papillary dermal edema, and perivascular lymphocytic inflammation involving the superficial and deep dermis (Fig. 2). The clinical and histopathologic features supported a diagnosis of Gianotti-Crosti syndrome (GCS).Serologic testing was negative for Epstein-Barr virus, parvovirus B19, hepatitis B or C, Coccidioides spp., Mycoplasma spp., rapid plasma reagin, Neisseria gonorrhoeae, Chlamydia trachomatis, and Streptococcus spp. An autoimmune evaluation showed normal levels of antinuclear antibody, cyclic citrullinated peptide, C-reactive protein, anti-SSA/Ro antibodies, anti-SSB/La antibodies, and double-stranded DNA.

Hydroxycarbamide (hydroxyurea) is an agent administered orally for the treatment of chronic myelogenous leukemia, myeloproliferative disorders, thalassemias, erythrocytosis, and sickle cell anemia [1][2][3]. An estimated 13% of patients with chronic myelogenous leukemia have mucocutaneous changes with long-term hydroxycarbamide therapy [4]. Myriad cutaneous adverse effects from long-term hydroxycarbamide therapy have been noted in the medical literature, including a dermatomyositis-like erythematous eruption on the hands, mucositis and oral ulceration, hair loss, nail pigmentation, and hyperpigmentation of the face [5]. The most common cutaneous adverse effect of long-term hydroxycarbamide therapy is painful lower-leg ulcers that typically appear spontaneously, involve the lateral malleoli and exhibit poor healing [6,7].A 62-year-old woman presented with an 18-month history of a painful and pruritic eruption on the dorsum of her hands. The patient's medical history showed myelodysplasia that had been treated with hydroxycarbamide for the past 5 years. Her hands showed shiny, violaceous papules over her knuckles and erythematous, reticulated, scaly plaques on her fingers and the dorsum of her hands (Image 1), mimicking Gottron papules and mechanic hands of dermatomyositis. Laboratory evaluation showed a negative result for antinuclear antibody and normal aldolase and creatine kinase values. A skin biopsy showed hyperkeratosis and epidermal atrophy. The basal layer showed vacuolar change and cytoid bodies. Direct immunofluorescence testing was negative for a lichenoid tissue reaction or lupus band.The skin eruption improved with use of a midpotency topical corticosteroid and discontinuation of hydroxycarbamide therapy. After 7 months of follow-up, only cutaneous atrophy remained. Unfortunately, the patient's myelodysplasia had progressed to acute myelogenous leukemia.Several terms have been used to describe the cutaneous changes of the hands associated with long-term hydroxycarbamide therapy, including hydroxyurea dermopathy, pseudoImage 1. Shiny, violaceous papules over the knuckles and erythematous, reticulated, scaly plaques on the fingers and the dorsum of the hands caused by reaction to long-term hydroxycarbamide therapy.