However, untreated PIH can last for months, years, or even be permanent if deeper layers of skin are affected. Even minimal skin exposure to the suns ultraviolet rays can sustain hyperpigmentation. Daily use of SPF 15 or higher sunscreen can minimize such a risk. Causes
Risk factors for the development of acne, other than genetics, have not been conclusively identified. Possible secondary contributors include hormones, infections, diet, and stress. Studies investigating the impact of smoking on the incidence and severity of acne have been inconclusive. Sunlight and cleanliness are not associated with acne. Genes
Acne appears to be highly heritable; genetics explain 81% of the variation in the population. Studies performed in affected twins and first-degree relatives further demonstrate the strongly inherited nature of acne. Acne susceptibility is likely due to the influence of multiple genes, as the disease does not follow a classic (Mendelian) inheritance pattern. These gene candidates include certain variations in tumor necrosis factor-alpha (TNF-alpha), IL-1 alpha, and CYP1A1 genes, among others. The 308 G/A single nucleotide polymorphism variation in the gene for TNF is associated with an increased risk for acne. Acne can be a feature of rare genetic disorders such as Aperts syndrome. Severe acne may be associated with XYY syndrome. Hormones
Hormonal activity, such as occurs during menstrual cycles and puberty, may contribute to the formation of acne. During puberty, an increase in sex hormones called androgens causes the skin follicle glands to grow larger and make more oily sebum.
It is necessary to mark drains in order to identify their location. They should be sutured with loops as well so it will be possible to advance them without re-anaesthetizing the patient while drains are re-sutured to the skin. An absorbent dressing is then applied. A bandnet dressing retainer can be constructed so as to prevent the use of tape. Other things to consider
Nutritional support
Adequate nutrition and hydration support is essential in any patient following surgery, particularly young children. In this case, pain and swelling in the neck region would usually cause difficulties in eating or swallowing, hence reducing patients food and fluid intake. Patients must therefore be well-nourished and hydrated to promote wound healing and to fight off infection. Post-operative care
Extubation, which is the removal of endotracheal tube to liberate the patient from mechanical ventilation, should only be done when the patients airway is proved to be patent, allowing adequate breathing. This is indicated by a decrease in swelling and patients capability of breathing adequately around an uncuffed endotracheal tube with the lumen blocked.During the hospital stay, patients condition will be closely monitored by:

carrying out cultures and sensitivity tests to decide if any changes need to be made to patients antibiotic course
observing for signs of further infection or sepsis including fevers, hypotension, and tachycardia
monitoring patients white blood cell count - a decrease implies effective and sufficient drainage
repeating CT scans to prove patients restored health status or if infection extends, the anatomical areas that are affected.