Nicolau syndrome (NS) or livedo-like dermatitis is a rare complication of injection of various medications such as penicillin. The pathophysiology of this events is not clear, but some hypotheses are suggested, such as sympathetic nerve stimulation, embolic occlusion, inflammation, or mechanical injury. In this paper we report 3 cases of NS following benzathine penicillin. Clinical symptoms imp...

A smooth curve γ : [0, 1] → S2 is locally convex if its geodesic curvature is positive at every point. J. A. Little showed that the space of all locally positive curves γ with γ(0) = γ(1) = e1 and γ ′(0) = γ′(1) = e2 has three connected components L−1,c, L+1, L−1,n. The space L−1,c is known to be contractible but the topology of the other two connected components is not well understood. We stud...

In 1920’s Marston Morse developed what is now known as Morse theory trying to study the topology of the space of closed curves on S2, see [7] and [5]. 80 years later a very similar problem about the topology of the space of closed and locally convex (i.e. without inflection points) curves on S2 is still widely open. The main difficulty is the absence of the covering homotopy principle for the m...

Post-injection abscess, which is the sad finale of Nicolau syndrome, continues to attract attention researchers due need clarify causes this iatrogenic disease in order develop effective measures for its prevention. For many years, from all over world have tried different perspectives explain mechanism drugs effect that post-injection pain infiltration, inflammation, erimatous skin damage, necr...

Nicolau syndrome is a rare complication of intramuscular injection that leads to local ischemic necrosis of the skin and adipose tissue. In this paper, we discuss etiologies, risk factors, and treatment options for gluteal Nicolau syndrome referring to patients treated in our hospital. Our study includes 17 women who visited our clinic with symptoms of gluteal necrosis secondary to intramuscula...