Introduction
Dissecting cellulitis of the scalp is a suppurative scalp condition with an unclear cause. It is presented with treatment challenges. Although spontaneous resolution may happen, it typically has a chronic history of unpredictable relapses. It is also known as Peri-folliculitis capitis abscedens et suffodiens. It mainly affects black men between the ages of 20 and 40. It can, however, also affect people of other races and/or women. Pus-filled and painful lumps appear. It often leads to scarring and patchy areas with permanent hair loss. Recurrence is problematic because it could last for several years. Other skin conditions, including acne, hidradenitis suppurative, or pilonidal cysts, can occasionally be linked to it (cysts near the cleft of the buttocks).
How Is Dissecting Cellulitis of the Scalp Caused?
The precise reason for the occurrence is not known. However, it is believed to be caused by the blockage of the scalp's hair follicles. After obstruction, material builds up in the follicle, resulting in swelling and rupture. An inflammatory reaction is brought on by the keratin (a skin protein) that is discharged from the damaged follicle. These lesions are susceptible to secondary infection, which can result in folliculitis or peri-folliculitis.
What Is the Clinical Presentation of Dissecting Cellulitis of the Scalp?
It typically starts off as a simple folliculitis, most frequently affecting the vertex and/or occiput, and progresses quickly to abscess and sinus formation from clusters of perifollicular pustules. Nodules can be firm or fluctuant and range in size from a few millimeters to several centimeters. Fluctuating nodules may express séropurulent fluid. Years may pass before lesions disappear, and they frequently do so with alopecia scarring. In most cases, no systemic signs are noticeable. Dissecting cellulitis of the scalp has a high chance of recurring. The signs and symptoms of the disease depend on the stage of the disease. They are:
-
Pustules around the follicles.
-
Nodules are tender. Some of these tender nodules release pus or blood.
-
Nodules with communicating sinuses.
-
Alopecia with scarring patches.
-
Dermoscopy (a technique to evaluate the skin) of alopecia patches in dissecting cellulitis of the scalp reveals regrowing hair, yellowish/white areas devoid of follicular openings, black dots, empty follicular openings, white dots, and red dots. Trichoscopy characteristics are controversial. However, they appear to be related to the severity and course of the condition.
-
Spondyloarthropathy has been documented. Hair loss from nodule surfaces and sparing in between the inflammatory sites is also observed. Regional lymphadenopathy is rarely observed.
How Is Dissecting Scalp Cellulitis Identified?
A dermatologist can usually identify the illness by looking at the scalp for clinical signs. Swabs of pus and plucked hair can be examined to rule out infections. In some circumstances, a scalp biopsy may be necessary.
What Is the Treatment for Dissecting Cellulitis of the Scalp or Perifolliculitis Capitis Abscedens et Suffodiens (PCAS)?
Dissecting cellulitis of the scalp is a persistent condition with an erratic course. PCAS is treated with a number of drugs. However, most of them have unsatisfactory outcomes.
1. Medication-As the etiology of dissecting cellulitis of the scalp is unknown, no single effective treatment is available. Antibiotics are not the usual course of treatment since bacterial infection is not a primary but a secondary infection. Intralesional steroid injections might be beneficial in the early stages of the condition.
-
Antibiotics - Doxycycline, ciprofloxacin, rifampicin, and dapsone are a few of the antibiotics successfully used in dissecting cellulitis of the scalp.
-
Intralesional Corticosteroids - To reduce inflammation, nodules and sinus tracts may be injected with intralesional corticosteroids (such as Triamcinolone acetonide). Intralesional corticosteroids should be considered as a temporizing therapy because their benefit is transient.
-
Oral Isotretinoin - One possible treatment option is oral Isotretinoin. Alitretinoin and Acitretin have also been used successfully orally in some cases. Treatment with Isotretinoin is generally lengthy and is carried on for a minimum of four months to avoid relapses and for the condition to become inactive.
2. Laser Ablation and Epilation - Good results were obtained while using carbon dioxide laser ablation (destroying or removing any body part or tissue) and epilation (removal of hairs of the body, including the root) of hair follicles. It was done using a long-pulse, non-Q-switched ruby laser and an 800-nm diode laser. Repeated sessions with a long-pulsed Nd: YAG laser were also employed for a select few patients, with some benefit.
3. Radiation Therapy - It has been stated that X-ray epilation works well. Patients with dissecting cellulitis of the scalp who received treatment with a modified version of external beam radiation had a positive outcome. Improvement of PCAS with brachytherapy treatment was described in research articles.
4. Surgical Excision - In severe or recalcitrant (uncooperative) situations, surgical removal of lesions should be taken into consideration. Large cysts and abscesses can either be removed or cut open and drained. Split-thickness skin grafting is also done. Both excision and skin grafting are the preferred treatment choices.
What Are the Problems Associated With Dissecting Cellulitis of the Scalp?
Dissecting cellulitis of the scalp may lead to other diseases involving obstruction, rupture, and inflammation of the hair follicles. The "follicular occlusion tetrad" consists of hidradenitis suppurativa (presence of boils and pus in the folds of the body), acne conglobata, which is a severe form of acne, and a pilonidal cyst (presence of infected cyst at the base of the spine). Moreover, these disorders can sporadically be accompanied by bone and joint inflammation (arthritis).
What Is the Outlook for Dissecting Cellulitis of the Scalp?
The condition is a chronic illness that can progress. Relapses are generally seen. A spontaneous resolution of the illness is possible, although it may take months or years and leave behind substantial scarring and permanent hair loss. The likelihood of making a full recovery from dissecting cellulitis of the scalp is low. Although the illness is not life-threatening, it is persistent and recurring. Problems can arise, and complications are seen as listed below:
-
Squamous Cell Carcinoma - While uncommon, it can be seen in persistent and recurring lesions of dissecting cellulitis of the scalp.
-
Permanent Hair Loss (Alopecia) - Alopecia is seen in scarred and persistently inflamed sites.
-
Marginal Keratitis - An inflammatory condition of the peripheral cornea known as marginal keratitis is characterized by peripheral stromal infiltrates that are frequently accompanied by epithelial breakdown and ulceration. It is clinically associated with dissecting cellulitis of the scalp.
Conclusion
Dissecting cellulitis of the scalp targets hair follicles and causes permanent hair loss in individuals. The exact cause is unknown, and the treatment effects may take time to reflect. A dermatologist will typically diagnose the problem after examining the scalp, but occasionally a biopsy performed local anesthetic agent may be necessary for confirmation.
