Background:Pyoderma gangrenosum is a rare inflammatory disease of unknown etiology and unspecific histopathology. There are no clear-cut criteria for the diagnosis of this disease. The diagnosis is usually made based on clinical appereance, course of disease and possible, commonly coexisting disorders. In atypical cases the diagnosis is based on exclusion of other causes of similar appearing cutaneous ulcerations.Main observations:The 67-year-old male patient, presented with a 15-year history of painful ulcers and vegetative lesions covered with sero-hemorrhagic and purulent secretions, localized on the dorsal surface of both hands leading to self-amputation of distal phalanges. We report a step-by-step The patient refers to have these complaints for more than 15 years. An extensive diagnostic procedure led to the diagnosis of pyoderma gangrenosum as a diagnosis of exclusion.Conclusion:This report shows an atypical variant of an ulcerative disease. Pyoderma gangrenosum, a diagnosis of exclusion, was sustained based on an extensive diagnostic procedure. In this article we describe the step-by-step approach which let to this diagnosis.

Background:Ustekinumab is a new immunosuppressive anti-psoriasis agent. The drug targets the p40 subunit of IL-12 and IL-23 and indirectly inhibits cytokine production by Th17 cells.Main observations:We present a case of a 36-year-old male patient with psoriasis, who received ustekinumab therapy, applied in 45mg subcutaneous injections at week 0, 4 and than every 12 weeks. After 7 months of therapy PASI decreased from 10,1 to 0,9. At this phase of therapy he developed two patches of alopecia areata on the scalp. The diagnosis was made based on clinical appearance and was confirmed by trichoscopy (hair and scalp dermoscopy) and reflectance confocal microscopy. The development of alopecia areata was preceded by emotional stress and dental infection. Conclusions:Ustekinumab seems an unlikely cause of alopecia areata in this patient. However, lack of efficacy is preventing hair loss may indicate that interleukin- 12 cytokine family is not a key player in pathogenesis of alopecia areata.

Background:Stevens-Johnson syndrome is an uncommon, acute life-threatening disease characterized by extensive epidermal sloughing and mucositis. In childhood, as in adulthood, this condition is mostly related to drugs, in particular antibiotics. Only a few cases reported were firmly attributed to infectious agents, mainly Mycoplasma pneumonia but the causative role of infectious microorganisms seems particularly relevant in pediatric patients. The seriousness of this condition imposes a prompt recognition and the early withdrawal of the potential causative drugs or the institution of directed measures against infectious agents (depending on the suspected etiology), as well as a supportive and more specific therapy. Some treatments claim to halt the progression of skin detachment, but remain of unproven benefit due to the lack of prospective, well controlled, randomized clinical trials.Main observations:We report a case of a 2-year-old boy admitted in our hospital for the treatment of an ependymoma of the posterior fossa, who developed a Stevens-Johnson syndrome associated most probably with a cytomegalovirus infection. He was successfully treated with high dose intravenous immunoglobulin and gancyclovir.Conclusion:To the best of our knowledge, this is the first case of SJS associated with CMV infection

Background:Polydactyly belongs to skeletal anomalies and may be a symptom of more complex genetic syndromes.Main observation:We observed an index case of ulnar hexadactyly of all four limbs in a 20-year-old man from India with three more brothersaffected in his family. No additional anomalies were observed. The diagnosis of a sporadic (ulnar) postaxial hexadactyly was made.Conclusion:Sporadic postaxial hexadactyly is one of the most common polydactylies in humans. In contrast, in the dermatologic literature the condition has only rarely been described.Conclusion:Presence of supernummary digits or toes, i.e. polydactyly, is seen occasionally in the dermatologic practise. The present case is extraordinary since all limbs were involved and the same was true for three of his brothers. If treatment is asked, hand surgery would be necessary.

Background:Aquagenic keratoderma is a rare transient disease that occurs after water immersion and disappears shortly after drying. Most cases involve the palms and fingers bilaterally but it can also affect the soles. Few cases have been associated with drugs but its pathogenesis remains unclear.Main observation:We report a 60-year-old man with a 30-year-history of aquagenic keratoderma of the right palm without associated hyperhidrosis or history of drug intake. After unsuccessful treatment with 15% aluminium chloride hexahydrate gel, botulinum toxin A injections led to significant improvement within 2 weeks.Conclusions:To our knowledge, this case is the first report of idiopathic unilateral aquagenic keratoderma in the medical literature. It is the third report of successful treatment with botulinum toxin A which is in favor of a role of sweat glands in the pathogenesis of aquagenic keratoderma.