Palisaded encapsulated neuroma (PEN) is a rare, benign cutaneous condition characterized by small, firm, non-pigmented nodules or papules. They typically occur as a solitary (single) lesion near the mucocutaneous junction of the skin of the face, although they can occur elsewhere on the body. Symptoms
PEN tumours are always painless, solid masses felt on the skin that, due to their slow-growing nature, typically take many years to grow to a size where they are noticeable. There are never any symptoms associated with systemic disease. Diagnosis
As mentioned previously, PEN is a benign, firm, flesh-coloured lesion that typically occurs in dermis of the skin of the face. The lesions are typically between 2–6mm and are slow-growing.On the face, the lesions can be found on the eyelid, nose and in the oral mucosa, however, the lesions can also occur on the shoulder, arm, hand, foot and the glans of the penis.PEN is diagnosed by clinical recognition of the lesion and on subsequent histologic examination. Typically, the lesions are suspected to be schwannomas or neurofibromas clinically with PEN being an incidental finding on histology.PEN is typically diagnosed in patients between the ages of 40 and 60 years and occurs more frequently in females than males. The diagnosis of PEN may be difficult, even with confirmatory histology, due to its histological similarities with schwannomas and neurofibromas.
DTaP-IPV/Hib vaccine is a 5-in-1 combination vaccine that protects against diphtheria, tetanus, whooping cough, polio, and Haemophilus influenzae type B.Its generic name is diphtheria and tetanus toxoids and acellular pertussis adsorbed, inactivated poliovirus and haemophilus B conjugate vaccine, and it is also known as DTaP-IPV-Hib. Uses
DTaP-IPV/Hib vaccine is administered to young children to immunise against diphtheria, tetanus, pertussis, poliomyelitis, and diseases caused by Haemophilus influenzae type B.

Formulations
A branded formulation marketed in the United States is Pentacel, manufactured by Sanofi Pasteur.Pentacel is known in the UK and Canada as Pediacel.An equivalent vaccine marketed in the UK and Canada by GlaxoSmithKline is Infanrix IPV + Hib. This is a two-part vaccine. The DTaP-IPV component is supplied as a sterile liquid, which is used to reconstitute lyophilized (freeze-dried) Hib vaccine. Pentaxim is a liquid formulation marketed by Sanofi Pasteur. Availability
It is only licensed for young children. In the US the FDA have approved the vaccine for children from age 6 weeks up to age 5 years. It was used in the UK until 2017, following which a 6-in-1 vaccine became available containing the additional protection against Hepatitis B. == References ==