One of the factors related to non-respondance is the presence of high levels of interferon beta neutralizing  antibodies. Interferon therapy, and specially interferon beta 1b, induces the production of  neutralizing  antibodies, usually in the second 6 months of treatment, in 5 to 30% of treated patients. Moreover, a subset of RRMS patients with specially active MS, sometimes called "rapidly worsening MS" are normally non-responders to interferon beta 1a.While more studies of the long-term effects of the drugs are needed,  existing data on the effects of interferons indicate that early-initiated long-term therapy is safe and it is related to better outcomes. Side effects
Interferon beta-1a is available only in injectable forms, and can cause skin reactions at the injection site that may include cutaneous necrosis. Skin reactions with interferon beta are more common with subcutaneous administration and vary greatly in their clinical presentation. They usually appear within the first month of treatment albeit their frequence and importance diminish after six months of treatment. Skin reactions are more prevalent in women. Mild skin reactions usually do not impede treatment whereas necroses appear in around 5% of patients and lead to the discontinuation of the therapy. Also over time, a visible dent at the injection site due to the local destruction of fat tissue, known as lipoatrophy, may develop, however, this rarely occurs with interferon treatment.Interferons, a subclass of cytokines, are produced in the body during illnesses such as influenza in order to help fight the infection.
However, concerns have been raised about the possibility of rare side effects like liver toxicity or interactions with other drugs; furthermore, the newer drug treatments tend to be more expensive than griseofulvin.On September 28, 2007, the U.S. Food and Drug Administration stated that Lamisil (Terbinafine hydrochloride, by Novartis AG) is a new treatment approved for use by children aged 4 years and older. The antifungal granules can be sprinkled on a childs food to treat the infection. Lamisil carries hepatotoxic risk, and can cause a metallic taste in the mouth. Epidemiology
Tinea capitis caused by species of Microsporum and Trichophyton is a contagious disease that is endemic in many countries. Affecting primarily pre-pubertal children between 6 and 10 years, it is more common in males than females; rarely does the disease persist past age sixteen. Because spread is thought to occur through direct contact with affected individuals, large outbreaks have been known to occur in schools and other places where children are in close quarters; however, indirect spread through contamination with infected objects (fomites) may also be a factor in the spread of infection. In the US, tinea capitis is thought to occur in 3-8% of the pediatric population; up to one-third of households with contact with an infected person may harbor the disease without showing any symptoms.The fungal species responsible for causing tinea capitis vary according to the geographical region, and may also change over time.